1 00:00:16,080 --> 00:00:17,590 okay uh 2 00:00:17,590 --> 00:00:17,600 okay uh 3 00:00:17,600 --> 00:00:20,310 okay uh some of the other methods of direct 4 00:00:20,310 --> 00:00:20,320 some of the other methods of direct 5 00:00:20,320 --> 00:00:23,269 some of the other methods of direct reading of fastener tension 6 00:00:23,269 --> 00:00:23,279 reading of fastener tension 7 00:00:23,279 --> 00:00:25,189 reading of fastener tension load cells 8 00:00:25,189 --> 00:00:25,199 load cells 9 00:00:25,199 --> 00:00:27,349 load cells and of course this 10 00:00:27,349 --> 00:00:27,359 and of course this 11 00:00:27,359 --> 00:00:29,269 and of course this pli 12 00:00:29,269 --> 00:00:29,279 pli 13 00:00:29,279 --> 00:00:31,509 pli preliminar or preload indicating washer 14 00:00:31,509 --> 00:00:31,519 preliminar or preload indicating washer 15 00:00:31,519 --> 00:00:33,830 preliminar or preload indicating washer that i described in the washer section 16 00:00:33,830 --> 00:00:33,840 that i described in the washer section 17 00:00:33,840 --> 00:00:36,069 that i described in the washer section is a mechanical load cell assembly and 18 00:00:36,069 --> 00:00:36,079 is a mechanical load cell assembly and 19 00:00:36,079 --> 00:00:38,229 is a mechanical load cell assembly and those can be used 20 00:00:38,229 --> 00:00:38,239 those can be used 21 00:00:38,239 --> 00:00:39,830 those can be used but of course in a lot of assemblies you 22 00:00:39,830 --> 00:00:39,840 but of course in a lot of assemblies you 23 00:00:39,840 --> 00:00:40,950 but of course in a lot of assemblies you don't have room enough to put all that 24 00:00:40,950 --> 00:00:40,960 don't have room enough to put all that 25 00:00:40,960 --> 00:00:43,110 don't have room enough to put all that stuff in 26 00:00:43,110 --> 00:00:43,120 stuff in 27 00:00:43,120 --> 00:00:44,630 stuff in because the amount of deformation in 28 00:00:44,630 --> 00:00:44,640 because the amount of deformation in 29 00:00:44,640 --> 00:00:46,310 because the amount of deformation in them has been correlated to specific 30 00:00:46,310 --> 00:00:46,320 them has been correlated to specific 31 00:00:46,320 --> 00:00:48,150 them has been correlated to specific tension load in the bolt 32 00:00:48,150 --> 00:00:48,160 tension load in the bolt 33 00:00:48,160 --> 00:00:50,709 tension load in the bolt now the skidmore will helm bolt tension 34 00:00:50,709 --> 00:00:50,719 now the skidmore will helm bolt tension 35 00:00:50,719 --> 00:00:53,590 now the skidmore will helm bolt tension measuring machine 36 00:00:53,590 --> 00:00:53,600 measuring machine 37 00:00:53,600 --> 00:00:55,670 measuring machine shown on the next page has a load cell 38 00:00:55,670 --> 00:00:55,680 shown on the next page has a load cell 39 00:00:55,680 --> 00:00:57,670 shown on the next page has a load cell in it to give a direct bolt tension 40 00:00:57,670 --> 00:00:57,680 in it to give a direct bolt tension 41 00:00:57,680 --> 00:01:00,069 in it to give a direct bolt tension reading for an applied torque now it's a 42 00:01:00,069 --> 00:01:00,079 reading for an applied torque now it's a 43 00:01:00,079 --> 00:01:02,069 reading for an applied torque now it's a bench top type 44 00:01:02,069 --> 00:01:02,079 bench top type 45 00:01:02,079 --> 00:01:04,390 bench top type uh setup which can be 46 00:01:04,390 --> 00:01:04,400 uh setup which can be 47 00:01:04,400 --> 00:01:06,550 uh setup which can be used at a construction site you just 48 00:01:06,550 --> 00:01:06,560 used at a construction site you just 49 00:01:06,560 --> 00:01:09,190 used at a construction site you just clamp it on to a beam and check some 50 00:01:09,190 --> 00:01:09,200 clamp it on to a beam and check some 51 00:01:09,200 --> 00:01:10,830 clamp it on to a beam and check some bolts and then you 52 00:01:10,830 --> 00:01:10,840 bolts and then you 53 00:01:10,840 --> 00:01:13,350 bolts and then you determine the torque that you want to 54 00:01:13,350 --> 00:01:13,360 determine the torque that you want to 55 00:01:13,360 --> 00:01:15,830 determine the torque that you want to put in that particular batch of bolts 56 00:01:15,830 --> 00:01:15,840 put in that particular batch of bolts 57 00:01:15,840 --> 00:01:24,070 put in that particular batch of bolts and use that for an installation 58 00:01:24,070 --> 00:01:24,080 59 00:01:24,080 --> 00:01:27,990 this company is uh here in uh cleveland 60 00:01:27,990 --> 00:01:28,000 this company is uh here in uh cleveland 61 00:01:28,000 --> 00:01:29,749 this company is uh here in uh cleveland uh 62 00:01:29,749 --> 00:01:29,759 uh 63 00:01:29,759 --> 00:01:32,230 uh the uh one of the owners of it attended 64 00:01:32,230 --> 00:01:32,240 the uh one of the owners of it attended 65 00:01:32,240 --> 00:01:34,630 the uh one of the owners of it attended uh last uh fastener conference we had 66 00:01:34,630 --> 00:01:34,640 uh last uh fastener conference we had 67 00:01:34,640 --> 00:01:35,749 uh last uh fastener conference we had here 68 00:01:35,749 --> 00:01:35,759 here 69 00:01:35,759 --> 00:01:37,670 here see it's a little job it just has the 70 00:01:37,670 --> 00:01:37,680 see it's a little job it just has the 71 00:01:37,680 --> 00:01:39,270 see it's a little job it just has the the clamps over here that you can clamp 72 00:01:39,270 --> 00:01:39,280 the clamps over here that you can clamp 73 00:01:39,280 --> 00:01:41,590 the clamps over here that you can clamp it on and it gives a direct reading of 74 00:01:41,590 --> 00:01:41,600 it on and it gives a direct reading of 75 00:01:41,600 --> 00:01:43,429 it on and it gives a direct reading of the number of pounds that you've put 76 00:01:43,429 --> 00:01:43,439 the number of pounds that you've put 77 00:01:43,439 --> 00:01:45,910 the number of pounds that you've put into the bolt so it 78 00:01:45,910 --> 00:01:45,920 into the bolt so it 79 00:01:45,920 --> 00:01:47,350 into the bolt so it it is a way 80 00:01:47,350 --> 00:01:47,360 it is a way 81 00:01:47,360 --> 00:01:49,030 it is a way of determining 82 00:01:49,030 --> 00:01:49,040 of determining 83 00:01:49,040 --> 00:01:50,789 of determining uh torque 84 00:01:50,789 --> 00:01:50,799 uh torque 85 00:01:50,799 --> 00:01:52,630 uh torque now here is 86 00:01:52,630 --> 00:01:52,640 now here is 87 00:01:52,640 --> 00:01:54,310 now here is here's another one that you don't think 88 00:01:54,310 --> 00:01:54,320 here's another one that you don't think 89 00:01:54,320 --> 00:01:57,590 here's another one that you don't think of it as being a uh 90 00:01:57,590 --> 00:01:57,600 of it as being a uh 91 00:01:57,600 --> 00:02:00,310 of it as being a uh direct reading but it is and i use this 92 00:02:00,310 --> 00:02:00,320 direct reading but it is and i use this 93 00:02:00,320 --> 00:02:02,069 direct reading but it is and i use this one i'll cover it later in the rivets 94 00:02:02,069 --> 00:02:02,079 one i'll cover it later in the rivets 95 00:02:02,079 --> 00:02:05,590 one i'll cover it later in the rivets section this is a high lock rivet 96 00:02:05,590 --> 00:02:05,600 section this is a high lock rivet 97 00:02:05,600 --> 00:02:07,990 section this is a high lock rivet and uh 98 00:02:07,990 --> 00:02:08,000 and uh 99 00:02:08,000 --> 00:02:10,229 and uh or a lock bolt it's actually a lock bolt 100 00:02:10,229 --> 00:02:10,239 or a lock bolt it's actually a lock bolt 101 00:02:10,239 --> 00:02:12,070 or a lock bolt it's actually a lock bolt pardon me rather than a rivet 102 00:02:12,070 --> 00:02:12,080 pardon me rather than a rivet 103 00:02:12,080 --> 00:02:13,990 pardon me rather than a rivet because it the shank does not expand on 104 00:02:13,990 --> 00:02:14,000 because it the shank does not expand on 105 00:02:14,000 --> 00:02:15,110 because it the shank does not expand on it 106 00:02:15,110 --> 00:02:15,120 it 107 00:02:15,120 --> 00:02:17,510 it but it has a 108 00:02:17,510 --> 00:02:17,520 but it has a 109 00:02:17,520 --> 00:02:20,630 but it has a it's a blind type fastener 110 00:02:20,630 --> 00:02:20,640 it's a blind type fastener 111 00:02:20,640 --> 00:02:23,670 it's a blind type fastener for installation and you have a hex key 112 00:02:23,670 --> 00:02:23,680 for installation and you have a hex key 113 00:02:23,680 --> 00:02:25,910 for installation and you have a hex key that holds it in place 114 00:02:25,910 --> 00:02:25,920 that holds it in place 115 00:02:25,920 --> 00:02:28,150 that holds it in place while you crank the nut on and when you 116 00:02:28,150 --> 00:02:28,160 while you crank the nut on and when you 117 00:02:28,160 --> 00:02:31,910 while you crank the nut on and when you get the nut to the proper torque limit 118 00:02:31,910 --> 00:02:31,920 get the nut to the proper torque limit 119 00:02:31,920 --> 00:02:33,830 get the nut to the proper torque limit it is notched here 120 00:02:33,830 --> 00:02:33,840 it is notched here 121 00:02:33,840 --> 00:02:37,030 it is notched here so that it snaps off breaks off so that 122 00:02:37,030 --> 00:02:37,040 so that it snaps off breaks off so that 123 00:02:37,040 --> 00:02:39,509 so that it snaps off breaks off so that is a self-limiting type 124 00:02:39,509 --> 00:02:39,519 is a self-limiting type 125 00:02:39,519 --> 00:02:41,990 is a self-limiting type that they have determined the 126 00:02:41,990 --> 00:02:42,000 that they have determined the 127 00:02:42,000 --> 00:02:44,949 that they have determined the right diameter for them 128 00:02:44,949 --> 00:02:44,959 right diameter for them 129 00:02:44,959 --> 00:02:46,630 right diameter for them so it will break off at the torque that 130 00:02:46,630 --> 00:02:46,640 so it will break off at the torque that 131 00:02:46,640 --> 00:02:52,710 so it will break off at the torque that you want 132 00:02:52,710 --> 00:02:52,720 133 00:02:52,720 --> 00:02:54,869 now here's one that i mentioned earlier 134 00:02:54,869 --> 00:02:54,879 now here's one that i mentioned earlier 135 00:02:54,879 --> 00:02:57,670 now here's one that i mentioned earlier the the dti bolt 136 00:02:57,670 --> 00:02:57,680 the the dti bolt 137 00:02:57,680 --> 00:03:00,949 the the dti bolt and the guy who has that company was at 138 00:03:00,949 --> 00:03:00,959 and the guy who has that company was at 139 00:03:00,959 --> 00:03:01,670 and the guy who has that company was at our 140 00:03:01,670 --> 00:03:01,680 our 141 00:03:01,680 --> 00:03:03,350 our one of our building technology council 142 00:03:03,350 --> 00:03:03,360 one of our building technology council 143 00:03:03,360 --> 00:03:05,430 one of our building technology council meetings 144 00:03:05,430 --> 00:03:05,440 meetings 145 00:03:05,440 --> 00:03:06,710 meetings this is a 146 00:03:06,710 --> 00:03:06,720 this is a 147 00:03:06,720 --> 00:03:10,710 this is a colored coated type bolt it has a 148 00:03:10,710 --> 00:03:10,720 colored coated type bolt it has a 149 00:03:10,720 --> 00:03:14,229 colored coated type bolt it has a little 150 00:03:14,229 --> 00:03:14,239 151 00:03:14,239 --> 00:03:17,509 gauge pin that's threaded inside it 152 00:03:17,509 --> 00:03:17,519 gauge pin that's threaded inside it 153 00:03:17,519 --> 00:03:19,350 gauge pin that's threaded inside it and then it has a 154 00:03:19,350 --> 00:03:19,360 and then it has a 155 00:03:19,360 --> 00:03:22,470 and then it has a an optical absorptance cell near the 156 00:03:22,470 --> 00:03:22,480 an optical absorptance cell near the 157 00:03:22,480 --> 00:03:23,589 an optical absorptance cell near the surface 158 00:03:23,589 --> 00:03:23,599 surface 159 00:03:23,599 --> 00:03:25,830 surface and as the cell changes thickness it 160 00:03:25,830 --> 00:03:25,840 and as the cell changes thickness it 161 00:03:25,840 --> 00:03:27,190 and as the cell changes thickness it changes color 162 00:03:27,190 --> 00:03:27,200 changes color 163 00:03:27,200 --> 00:03:27,910 changes color so 164 00:03:27,910 --> 00:03:27,920 so 165 00:03:27,920 --> 00:03:29,270 so as you 166 00:03:29,270 --> 00:03:29,280 as you 167 00:03:29,280 --> 00:03:32,470 as you elongate the bolt it pulls this gauge 168 00:03:32,470 --> 00:03:32,480 elongate the bolt it pulls this gauge 169 00:03:32,480 --> 00:03:35,270 elongate the bolt it pulls this gauge away from the cell 170 00:03:35,270 --> 00:03:35,280 away from the cell 171 00:03:35,280 --> 00:03:37,270 away from the cell and gives you a color-coded load 172 00:03:37,270 --> 00:03:37,280 and gives you a color-coded load 173 00:03:37,280 --> 00:03:40,070 and gives you a color-coded load indication so you turn the thing until 174 00:03:40,070 --> 00:03:40,080 indication so you turn the thing until 175 00:03:40,080 --> 00:03:42,869 indication so you turn the thing until it shows red or whatever and you're all 176 00:03:42,869 --> 00:03:42,879 it shows red or whatever and you're all 177 00:03:42,879 --> 00:03:44,309 it shows red or whatever and you're all right but of course 178 00:03:44,309 --> 00:03:44,319 right but of course 179 00:03:44,319 --> 00:03:46,390 right but of course the problem with a bolt like this you 180 00:03:46,390 --> 00:03:46,400 the problem with a bolt like this you 181 00:03:46,400 --> 00:03:48,470 the problem with a bolt like this you can imagine how expensive it is compared 182 00:03:48,470 --> 00:03:48,480 can imagine how expensive it is compared 183 00:03:48,480 --> 00:03:50,229 can imagine how expensive it is compared to a hardware store bolt 184 00:03:50,229 --> 00:03:50,239 to a hardware store bolt 185 00:03:50,239 --> 00:03:52,550 to a hardware store bolt and it's got to be big enough that you 186 00:03:52,550 --> 00:03:52,560 and it's got to be big enough that you 187 00:03:52,560 --> 00:03:54,309 and it's got to be big enough that you can drill the center of it to put that 188 00:03:54,309 --> 00:03:54,319 can drill the center of it to put that 189 00:03:54,319 --> 00:03:56,710 can drill the center of it to put that stuff in so the minimum size for it is a 190 00:03:56,710 --> 00:03:56,720 stuff in so the minimum size for it is a 191 00:03:56,720 --> 00:04:02,070 stuff in so the minimum size for it is a half inch diameter 192 00:04:02,070 --> 00:04:02,080 193 00:04:02,080 --> 00:04:05,190 now we move on to design criteria 194 00:04:05,190 --> 00:04:05,200 now we move on to design criteria 195 00:04:05,200 --> 00:04:06,710 now we move on to design criteria and 196 00:04:06,710 --> 00:04:06,720 and 197 00:04:06,720 --> 00:04:09,589 and this first line is one of my pet peeves 198 00:04:09,589 --> 00:04:09,599 this first line is one of my pet peeves 199 00:04:09,599 --> 00:04:12,550 this first line is one of my pet peeves i think that we don't spend enough time 200 00:04:12,550 --> 00:04:12,560 i think that we don't spend enough time 201 00:04:12,560 --> 00:04:17,189 i think that we don't spend enough time looking at something before we design it 202 00:04:17,189 --> 00:04:17,199 203 00:04:17,199 --> 00:04:18,870 we should think about it look at it 204 00:04:18,870 --> 00:04:18,880 we should think about it look at it 205 00:04:18,880 --> 00:04:20,949 we should think about it look at it first now of course working with the 206 00:04:20,949 --> 00:04:20,959 first now of course working with the 207 00:04:20,959 --> 00:04:23,270 first now of course working with the research people around here you usually 208 00:04:23,270 --> 00:04:23,280 research people around here you usually 209 00:04:23,280 --> 00:04:23,990 research people around here you usually do 210 00:04:23,990 --> 00:04:24,000 do 211 00:04:24,000 --> 00:04:27,510 do designs by an iterative process because 212 00:04:27,510 --> 00:04:27,520 designs by an iterative process because 213 00:04:27,520 --> 00:04:29,189 designs by an iterative process because when they come to you about something 214 00:04:29,189 --> 00:04:29,199 when they come to you about something 215 00:04:29,199 --> 00:04:30,710 when they come to you about something usually they don't know and i'm not 216 00:04:30,710 --> 00:04:30,720 usually they don't know and i'm not 217 00:04:30,720 --> 00:04:34,550 usually they don't know and i'm not saying this as a 218 00:04:34,550 --> 00:04:34,560 219 00:04:34,560 --> 00:04:36,710 degrading remark they don't know exactly 220 00:04:36,710 --> 00:04:36,720 degrading remark they don't know exactly 221 00:04:36,720 --> 00:04:38,310 degrading remark they don't know exactly what they want so they tell you what 222 00:04:38,310 --> 00:04:38,320 what they want so they tell you what 223 00:04:38,320 --> 00:04:39,830 what they want so they tell you what they think they want and then you take 224 00:04:39,830 --> 00:04:39,840 they think they want and then you take 225 00:04:39,840 --> 00:04:41,830 they think they want and then you take it from there and usually what happens 226 00:04:41,830 --> 00:04:41,840 it from there and usually what happens 227 00:04:41,840 --> 00:04:44,390 it from there and usually what happens is you by iterative process 228 00:04:44,390 --> 00:04:44,400 is you by iterative process 229 00:04:44,400 --> 00:04:47,909 is you by iterative process you come up with the actual requirements 230 00:04:47,909 --> 00:04:47,919 you come up with the actual requirements 231 00:04:47,919 --> 00:04:50,150 you come up with the actual requirements and that's something that you should do 232 00:04:50,150 --> 00:04:50,160 and that's something that you should do 233 00:04:50,160 --> 00:04:52,469 and that's something that you should do on any design you should sit down first 234 00:04:52,469 --> 00:04:52,479 on any design you should sit down first 235 00:04:52,479 --> 00:04:54,310 on any design you should sit down first and look at it 236 00:04:54,310 --> 00:04:54,320 and look at it 237 00:04:54,320 --> 00:04:56,629 and look at it decide what you really need 238 00:04:56,629 --> 00:04:56,639 decide what you really need 239 00:04:56,639 --> 00:04:59,030 decide what you really need and then look at the accepted design 240 00:04:59,030 --> 00:04:59,040 and then look at the accepted design 241 00:04:59,040 --> 00:05:00,870 and then look at the accepted design practices from both the layout and 242 00:05:00,870 --> 00:05:00,880 practices from both the layout and 243 00:05:00,880 --> 00:05:02,790 practices from both the layout and analytical standpoints 244 00:05:02,790 --> 00:05:02,800 analytical standpoints 245 00:05:02,800 --> 00:05:09,270 analytical standpoints to see what you should do 246 00:05:09,270 --> 00:05:09,280 247 00:05:09,280 --> 00:05:11,270 now here's here's one of the questions 248 00:05:11,270 --> 00:05:11,280 now here's here's one of the questions 249 00:05:11,280 --> 00:05:14,310 now here's here's one of the questions that comes up sometimes is diameter 250 00:05:14,310 --> 00:05:14,320 that comes up sometimes is diameter 251 00:05:14,320 --> 00:05:17,350 that comes up sometimes is diameter versus length on fasteners 252 00:05:17,350 --> 00:05:17,360 versus length on fasteners 253 00:05:17,360 --> 00:05:19,749 versus length on fasteners and uh 254 00:05:19,749 --> 00:05:19,759 and uh 255 00:05:19,759 --> 00:05:21,909 and uh we're always faced with decisions on do 256 00:05:21,909 --> 00:05:21,919 we're always faced with decisions on do 257 00:05:21,919 --> 00:05:24,469 we're always faced with decisions on do you use off-the-shelf stuff 258 00:05:24,469 --> 00:05:24,479 you use off-the-shelf stuff 259 00:05:24,479 --> 00:05:27,270 you use off-the-shelf stuff or do you custom design it 260 00:05:27,270 --> 00:05:27,280 or do you custom design it 261 00:05:27,280 --> 00:05:28,790 or do you custom design it well 262 00:05:28,790 --> 00:05:28,800 well 263 00:05:28,800 --> 00:05:31,430 well a good way to look at it is to check and 264 00:05:31,430 --> 00:05:31,440 a good way to look at it is to check and 265 00:05:31,440 --> 00:05:33,909 a good way to look at it is to check and see what's available first see if you 266 00:05:33,909 --> 00:05:33,919 see what's available first see if you 267 00:05:33,919 --> 00:05:35,430 see what's available first see if you can 268 00:05:35,430 --> 00:05:35,440 can 269 00:05:35,440 --> 00:05:37,510 can build your design around that without 270 00:05:37,510 --> 00:05:37,520 build your design around that without 271 00:05:37,520 --> 00:05:39,670 build your design around that without having to buy special 272 00:05:39,670 --> 00:05:39,680 having to buy special 273 00:05:39,680 --> 00:05:41,670 having to buy special components 274 00:05:41,670 --> 00:05:41,680 components 275 00:05:41,680 --> 00:05:42,710 components and 276 00:05:42,710 --> 00:05:42,720 and 277 00:05:42,720 --> 00:05:43,590 and so 278 00:05:43,590 --> 00:05:43,600 so 279 00:05:43,600 --> 00:05:46,310 so one of the things that 280 00:05:46,310 --> 00:05:46,320 one of the things that 281 00:05:46,320 --> 00:05:49,189 one of the things that you look at is the length to diameter 282 00:05:49,189 --> 00:05:49,199 you look at is the length to diameter 283 00:05:49,199 --> 00:05:50,629 you look at is the length to diameter ratio 284 00:05:50,629 --> 00:05:50,639 ratio 285 00:05:50,639 --> 00:05:51,749 ratio of 286 00:05:51,749 --> 00:05:51,759 of 287 00:05:51,759 --> 00:05:54,230 of because if you want to use a 10 inch 288 00:05:54,230 --> 00:05:54,240 because if you want to use a 10 inch 289 00:05:54,240 --> 00:05:55,430 because if you want to use a 10 inch fastener that's a quarter inch in 290 00:05:55,430 --> 00:05:55,440 fastener that's a quarter inch in 291 00:05:55,440 --> 00:05:57,350 fastener that's a quarter inch in diameter 292 00:05:57,350 --> 00:05:57,360 diameter 293 00:05:57,360 --> 00:05:58,870 diameter and you don't want to make it out of 294 00:05:58,870 --> 00:05:58,880 and you don't want to make it out of 295 00:05:58,880 --> 00:06:00,710 and you don't want to make it out of threaded rod 296 00:06:00,710 --> 00:06:00,720 threaded rod 297 00:06:00,720 --> 00:06:01,830 threaded rod you're in trouble because you're going 298 00:06:01,830 --> 00:06:01,840 you're in trouble because you're going 299 00:06:01,840 --> 00:06:05,110 you're in trouble because you're going to have to get one that's custom made 300 00:06:05,110 --> 00:06:05,120 to have to get one that's custom made 301 00:06:05,120 --> 00:06:08,150 to have to get one that's custom made usually the l over d ratio is up to 302 00:06:08,150 --> 00:06:08,160 usually the l over d ratio is up to 303 00:06:08,160 --> 00:06:10,469 usually the l over d ratio is up to about 12 304 00:06:10,469 --> 00:06:10,479 about 12 305 00:06:10,479 --> 00:06:14,629 about 12 and uh it's limited somewhat by the 306 00:06:14,629 --> 00:06:14,639 and uh it's limited somewhat by the 307 00:06:14,639 --> 00:06:16,950 and uh it's limited somewhat by the capacity of the automatic screw forming 308 00:06:16,950 --> 00:06:16,960 capacity of the automatic screw forming 309 00:06:16,960 --> 00:06:19,909 capacity of the automatic screw forming machines because you can't put a long 310 00:06:19,909 --> 00:06:19,919 machines because you can't put a long 311 00:06:19,919 --> 00:06:21,749 machines because you can't put a long skinny fastener through there and do it 312 00:06:21,749 --> 00:06:21,759 skinny fastener through there and do it 313 00:06:21,759 --> 00:06:23,990 skinny fastener through there and do it on an automated basis 314 00:06:23,990 --> 00:06:24,000 on an automated basis 315 00:06:24,000 --> 00:06:28,309 on an automated basis so we have a table here that lists 316 00:06:28,309 --> 00:06:28,319 so we have a table here that lists 317 00:06:28,319 --> 00:06:29,670 so we have a table here that lists common 318 00:06:29,670 --> 00:06:29,680 common 319 00:06:29,680 --> 00:06:31,029 common fasteners 320 00:06:31,029 --> 00:06:31,039 fasteners 321 00:06:31,039 --> 00:06:33,029 fasteners availability now these are industrial 322 00:06:33,029 --> 00:06:33,039 availability now these are industrial 323 00:06:33,039 --> 00:06:34,710 availability now these are industrial fasteners 324 00:06:34,710 --> 00:06:34,720 fasteners 325 00:06:34,720 --> 00:06:36,629 fasteners not aerospace 326 00:06:36,629 --> 00:06:36,639 not aerospace 327 00:06:36,639 --> 00:06:37,430 not aerospace and 328 00:06:37,430 --> 00:06:37,440 and 329 00:06:37,440 --> 00:06:38,230 and the 330 00:06:38,230 --> 00:06:38,240 the 331 00:06:38,240 --> 00:06:40,309 the one asterix 332 00:06:40,309 --> 00:06:40,319 one asterix 333 00:06:40,319 --> 00:06:42,870 one asterix represents the stock sizes of maximum 334 00:06:42,870 --> 00:06:42,880 represents the stock sizes of maximum 335 00:06:42,880 --> 00:06:45,830 represents the stock sizes of maximum demand so you see if you're in this this 336 00:06:45,830 --> 00:06:45,840 demand so you see if you're in this this 337 00:06:45,840 --> 00:06:48,390 demand so you see if you're in this this area if you need a 338 00:06:48,390 --> 00:06:48,400 area if you need a 339 00:06:48,400 --> 00:06:50,230 area if you need a 3 8 diameter 340 00:06:50,230 --> 00:06:50,240 3 8 diameter 341 00:06:50,240 --> 00:06:52,150 3 8 diameter with an inch or inch and a quarter 342 00:06:52,150 --> 00:06:52,160 with an inch or inch and a quarter 343 00:06:52,160 --> 00:06:53,990 with an inch or inch and a quarter length you got it 344 00:06:53,990 --> 00:06:54,000 length you got it 345 00:06:54,000 --> 00:06:56,469 length you got it two asterisks represents the ones less 346 00:06:56,469 --> 00:06:56,479 two asterisks represents the ones less 347 00:06:56,479 --> 00:06:58,550 two asterisks represents the ones less frequently used so if you want say a 348 00:06:58,550 --> 00:06:58,560 frequently used so if you want say a 349 00:06:58,560 --> 00:07:00,230 frequently used so if you want say a quarter inch and an inch and three 350 00:07:00,230 --> 00:07:00,240 quarter inch and an inch and three 351 00:07:00,240 --> 00:07:01,189 quarter inch and an inch and three quarter 352 00:07:01,189 --> 00:07:01,199 quarter 353 00:07:01,199 --> 00:07:03,510 quarter length you might have a little trouble 354 00:07:03,510 --> 00:07:03,520 length you might have a little trouble 355 00:07:03,520 --> 00:07:05,510 length you might have a little trouble all the rest of them are considered 356 00:07:05,510 --> 00:07:05,520 all the rest of them are considered 357 00:07:05,520 --> 00:07:06,710 all the rest of them are considered specials 358 00:07:06,710 --> 00:07:06,720 specials 359 00:07:06,720 --> 00:07:09,510 specials so if you want a quarter inch 360 00:07:09,510 --> 00:07:09,520 so if you want a quarter inch 361 00:07:09,520 --> 00:07:12,230 so if you want a quarter inch by six inch look look how deep of 362 00:07:12,230 --> 00:07:12,240 by six inch look look how deep of 363 00:07:12,240 --> 00:07:13,830 by six inch look look how deep of trouble you're in down here because you 364 00:07:13,830 --> 00:07:13,840 trouble you're in down here because you 365 00:07:13,840 --> 00:07:15,990 trouble you're in down here because you can't get it unless you pay special for 366 00:07:15,990 --> 00:07:16,000 can't get it unless you pay special for 367 00:07:16,000 --> 00:07:16,950 can't get it unless you pay special for it 368 00:07:16,950 --> 00:07:16,960 it 369 00:07:16,960 --> 00:07:20,070 it and i know we had some 370 00:07:20,070 --> 00:07:20,080 and i know we had some 371 00:07:20,080 --> 00:07:21,909 and i know we had some fasteners on a job that we did here one 372 00:07:21,909 --> 00:07:21,919 fasteners on a job that we did here one 373 00:07:21,919 --> 00:07:23,589 fasteners on a job that we did here one time that were quarter inch stainless 374 00:07:23,589 --> 00:07:23,599 time that were quarter inch stainless 375 00:07:23,599 --> 00:07:25,749 time that were quarter inch stainless steel that had to be i believe 376 00:07:25,749 --> 00:07:25,759 steel that had to be i believe 377 00:07:25,759 --> 00:07:27,749 steel that had to be i believe six inches or five and a half inches or 378 00:07:27,749 --> 00:07:27,759 six inches or five and a half inches or 379 00:07:27,759 --> 00:07:29,350 six inches or five and a half inches or six inches long 380 00:07:29,350 --> 00:07:29,360 six inches long 381 00:07:29,360 --> 00:07:30,950 six inches long we had to pay special for them and took 382 00:07:30,950 --> 00:07:30,960 we had to pay special for them and took 383 00:07:30,960 --> 00:07:33,270 we had to pay special for them and took a long time to get them now when i say 384 00:07:33,270 --> 00:07:33,280 a long time to get them now when i say 385 00:07:33,280 --> 00:07:35,589 a long time to get them now when i say these are industrial type fasteners on 386 00:07:35,589 --> 00:07:35,599 these are industrial type fasteners on 387 00:07:35,599 --> 00:07:38,629 these are industrial type fasteners on the aerospace fasteners the links there 388 00:07:38,629 --> 00:07:38,639 the aerospace fasteners the links there 389 00:07:38,639 --> 00:07:41,430 the aerospace fasteners the links there are graduated in sixteenths 390 00:07:41,430 --> 00:07:41,440 are graduated in sixteenths 391 00:07:41,440 --> 00:07:43,990 are graduated in sixteenths uh the different specified dash number 392 00:07:43,990 --> 00:07:44,000 uh the different specified dash number 393 00:07:44,000 --> 00:07:46,309 uh the different specified dash number that gives you the 394 00:07:46,309 --> 00:07:46,319 that gives you the 395 00:07:46,319 --> 00:07:48,790 that gives you the grip length of the fastener in 396 00:07:48,790 --> 00:07:48,800 grip length of the fastener in 397 00:07:48,800 --> 00:07:52,070 grip length of the fastener in sixteenths but just because somebody 398 00:07:52,070 --> 00:07:52,080 sixteenths but just because somebody 399 00:07:52,080 --> 00:07:53,830 sixteenths but just because somebody shows it in their catalog doesn't mean 400 00:07:53,830 --> 00:07:53,840 shows it in their catalog doesn't mean 401 00:07:53,840 --> 00:07:55,830 shows it in their catalog doesn't mean that they have it either so if you need 402 00:07:55,830 --> 00:07:55,840 that they have it either so if you need 403 00:07:55,840 --> 00:07:58,950 that they have it either so if you need something that's an oddball type uh 404 00:07:58,950 --> 00:07:58,960 something that's an oddball type uh 405 00:07:58,960 --> 00:08:01,029 something that's an oddball type uh length to diameter you still are going 406 00:08:01,029 --> 00:08:01,039 length to diameter you still are going 407 00:08:01,039 --> 00:08:04,309 length to diameter you still are going to have to to pay special for it now 408 00:08:04,309 --> 00:08:04,319 to have to to pay special for it now 409 00:08:04,319 --> 00:08:06,230 to have to to pay special for it now here's a little handy dandy thing that 410 00:08:06,230 --> 00:08:06,240 here's a little handy dandy thing that 411 00:08:06,240 --> 00:08:08,790 here's a little handy dandy thing that uh once again i 412 00:08:08,790 --> 00:08:08,800 uh once again i 413 00:08:08,800 --> 00:08:11,029 uh once again i got it from one of these guys at martin 414 00:08:11,029 --> 00:08:11,039 got it from one of these guys at martin 415 00:08:11,039 --> 00:08:12,710 got it from one of these guys at martin when i worked there 416 00:08:12,710 --> 00:08:12,720 when i worked there 417 00:08:12,720 --> 00:08:14,550 when i worked there and i've never seen this anywhere either 418 00:08:14,550 --> 00:08:14,560 and i've never seen this anywhere either 419 00:08:14,560 --> 00:08:17,430 and i've never seen this anywhere either is a way of calculating the number 420 00:08:17,430 --> 00:08:17,440 is a way of calculating the number 421 00:08:17,440 --> 00:08:19,430 is a way of calculating the number fastener diameter 422 00:08:19,430 --> 00:08:19,440 fastener diameter 423 00:08:19,440 --> 00:08:21,749 fastener diameter i put it in my fastener manual so a lot 424 00:08:21,749 --> 00:08:21,759 i put it in my fastener manual so a lot 425 00:08:21,759 --> 00:08:24,629 i put it in my fastener manual so a lot of you guys have already seen it but 426 00:08:24,629 --> 00:08:24,639 of you guys have already seen it but 427 00:08:24,639 --> 00:08:26,790 of you guys have already seen it but in order to calculate it this is for 428 00:08:26,790 --> 00:08:26,800 in order to calculate it this is for 429 00:08:26,800 --> 00:08:29,990 in order to calculate it this is for inches of course you take 60 thousandths 430 00:08:29,990 --> 00:08:30,000 inches of course you take 60 thousandths 431 00:08:30,000 --> 00:08:33,670 inches of course you take 60 thousandths plus 13 thousandths times n where n is 432 00:08:33,670 --> 00:08:33,680 plus 13 thousandths times n where n is 433 00:08:33,680 --> 00:08:35,909 plus 13 thousandths times n where n is the number of the fastener 434 00:08:35,909 --> 00:08:35,919 the number of the fastener 435 00:08:35,919 --> 00:08:39,509 the number of the fastener and that'll give you the total od of it 436 00:08:39,509 --> 00:08:39,519 and that'll give you the total od of it 437 00:08:39,519 --> 00:08:41,509 and that'll give you the total od of it and i the example i give here is a 438 00:08:41,509 --> 00:08:41,519 and i the example i give here is a 439 00:08:41,519 --> 00:08:43,990 and i the example i give here is a number eight fastener you take sixty 440 00:08:43,990 --> 00:08:44,000 number eight fastener you take sixty 441 00:08:44,000 --> 00:08:45,670 number eight fastener you take sixty thousandths plus thirteen thousands 442 00:08:45,670 --> 00:08:45,680 thousandths plus thirteen thousands 443 00:08:45,680 --> 00:08:48,389 thousandths plus thirteen thousands times eight gives you a 164. so if 444 00:08:48,389 --> 00:08:48,399 times eight gives you a 164. so if 445 00:08:48,399 --> 00:08:51,030 times eight gives you a 164. so if somebody says i got a number six 446 00:08:51,030 --> 00:08:51,040 somebody says i got a number six 447 00:08:51,040 --> 00:08:53,590 somebody says i got a number six or a number four you can calculate the 448 00:08:53,590 --> 00:08:53,600 or a number four you can calculate the 449 00:08:53,600 --> 00:08:56,230 or a number four you can calculate the decimal diameter of it directly that way 450 00:08:56,230 --> 00:08:56,240 decimal diameter of it directly that way 451 00:08:56,240 --> 00:08:57,430 decimal diameter of it directly that way just by keeping that in mind of course 452 00:08:57,430 --> 00:08:57,440 just by keeping that in mind of course 453 00:08:57,440 --> 00:08:59,269 just by keeping that in mind of course the number 10 is easy 454 00:08:59,269 --> 00:08:59,279 the number 10 is easy 455 00:08:59,279 --> 00:09:03,590 the number 10 is easy because 130 plus 60 is 190. 456 00:09:03,590 --> 00:09:03,600 457 00:09:03,600 --> 00:09:05,350 and 458 00:09:05,350 --> 00:09:05,360 and 459 00:09:05,360 --> 00:09:07,750 and for those of you who are 460 00:09:07,750 --> 00:09:07,760 for those of you who are 461 00:09:07,760 --> 00:09:09,990 for those of you who are haven't seen them before they even have 462 00:09:09,990 --> 00:09:10,000 haven't seen them before they even have 463 00:09:10,000 --> 00:09:12,710 haven't seen them before they even have number 12 fasteners 464 00:09:12,710 --> 00:09:12,720 number 12 fasteners 465 00:09:12,720 --> 00:09:15,670 number 12 fasteners which is i believe works out to be 0.216 466 00:09:15,670 --> 00:09:15,680 which is i believe works out to be 0.216 467 00:09:15,680 --> 00:09:17,269 which is i believe works out to be 0.216 or something like that the automotive 468 00:09:17,269 --> 00:09:17,279 or something like that the automotive 469 00:09:17,279 --> 00:09:19,910 or something like that the automotive industry uses them some and i ran into 470 00:09:19,910 --> 00:09:19,920 industry uses them some and i ran into 471 00:09:19,920 --> 00:09:21,509 industry uses them some and i ran into some of them one time and i couldn't 472 00:09:21,509 --> 00:09:21,519 some of them one time and i couldn't 473 00:09:21,519 --> 00:09:23,829 some of them one time and i couldn't figure out what they were way back years 474 00:09:23,829 --> 00:09:23,839 figure out what they were way back years 475 00:09:23,839 --> 00:09:25,350 figure out what they were way back years years ago until i figured out it was a 476 00:09:25,350 --> 00:09:25,360 years ago until i figured out it was a 477 00:09:25,360 --> 00:09:26,870 years ago until i figured out it was a number 12 478 00:09:26,870 --> 00:09:26,880 number 12 479 00:09:26,880 --> 00:09:29,670 number 12 but they're they're not a normal one 480 00:09:29,670 --> 00:09:29,680 but they're they're not a normal one 481 00:09:29,680 --> 00:09:32,470 but they're they're not a normal one now clearance holes for fasteners 482 00:09:32,470 --> 00:09:32,480 now clearance holes for fasteners 483 00:09:32,480 --> 00:09:34,870 now clearance holes for fasteners for shear applications 484 00:09:34,870 --> 00:09:34,880 for shear applications 485 00:09:34,880 --> 00:09:38,150 for shear applications the clearance should be minimized 486 00:09:38,150 --> 00:09:38,160 the clearance should be minimized 487 00:09:38,160 --> 00:09:41,590 the clearance should be minimized and uh ideally the hole should be max 488 00:09:41,590 --> 00:09:41,600 and uh ideally the hole should be max 489 00:09:41,600 --> 00:09:43,590 and uh ideally the hole should be max drilled 490 00:09:43,590 --> 00:09:43,600 drilled 491 00:09:43,600 --> 00:09:45,670 drilled and the material thickness and fastener 492 00:09:45,670 --> 00:09:45,680 and the material thickness and fastener 493 00:09:45,680 --> 00:09:47,030 and the material thickness and fastener strength should be sized to make the 494 00:09:47,030 --> 00:09:47,040 strength should be sized to make the 495 00:09:47,040 --> 00:09:48,870 strength should be sized to make the fasteners critical in bearing rather 496 00:09:48,870 --> 00:09:48,880 fasteners critical in bearing rather 497 00:09:48,880 --> 00:09:52,150 fasteners critical in bearing rather than shear that means that if you pull 498 00:09:52,150 --> 00:09:52,160 than shear that means that if you pull 499 00:09:52,160 --> 00:09:54,310 than shear that means that if you pull and shear on the joint 500 00:09:54,310 --> 00:09:54,320 and shear on the joint 501 00:09:54,320 --> 00:09:55,590 and shear on the joint that the 502 00:09:55,590 --> 00:09:55,600 that the 503 00:09:55,600 --> 00:09:57,430 that the fastener is stronger than the material 504 00:09:57,430 --> 00:09:57,440 fastener is stronger than the material 505 00:09:57,440 --> 00:10:00,070 fastener is stronger than the material it's in so it will elongate the hole so 506 00:10:00,070 --> 00:10:00,080 it's in so it will elongate the hole so 507 00:10:00,080 --> 00:10:02,790 it's in so it will elongate the hole so it can load up the other fasteners 508 00:10:02,790 --> 00:10:02,800 it can load up the other fasteners 509 00:10:02,800 --> 00:10:05,829 it can load up the other fasteners and uh in tension applications you don't 510 00:10:05,829 --> 00:10:05,839 and uh in tension applications you don't 511 00:10:05,839 --> 00:10:07,910 and uh in tension applications you don't have to worry about that if it's if you 512 00:10:07,910 --> 00:10:07,920 have to worry about that if it's if you 513 00:10:07,920 --> 00:10:09,670 have to worry about that if it's if you can assure yourself that you have enough 514 00:10:09,670 --> 00:10:09,680 can assure yourself that you have enough 515 00:10:09,680 --> 00:10:11,829 can assure yourself that you have enough tension in it enough friction that the 516 00:10:11,829 --> 00:10:11,839 tension in it enough friction that the 517 00:10:11,839 --> 00:10:13,350 tension in it enough friction that the joint won't move 518 00:10:13,350 --> 00:10:13,360 joint won't move 519 00:10:13,360 --> 00:10:16,230 joint won't move then you can have a looser fit on it 520 00:10:16,230 --> 00:10:16,240 then you can have a looser fit on it 521 00:10:16,240 --> 00:10:18,310 then you can have a looser fit on it then then your main concern is prevent 522 00:10:18,310 --> 00:10:18,320 then then your main concern is prevent 523 00:10:18,320 --> 00:10:20,550 then then your main concern is prevent the fastener head or the nut from 524 00:10:20,550 --> 00:10:20,560 the fastener head or the nut from 525 00:10:20,560 --> 00:10:21,990 the fastener head or the nut from pulling through the hole or something 526 00:10:21,990 --> 00:10:22,000 pulling through the hole or something 527 00:10:22,000 --> 00:10:24,550 pulling through the hole or something like that or embedding in it now on the 528 00:10:24,550 --> 00:10:24,560 like that or embedding in it now on the 529 00:10:24,560 --> 00:10:27,509 like that or embedding in it now on the next page 530 00:10:27,509 --> 00:10:27,519 531 00:10:27,519 --> 00:10:30,069 fred yaris's group was kind enough to 532 00:10:30,069 --> 00:10:30,079 fred yaris's group was kind enough to 533 00:10:30,079 --> 00:10:31,750 fred yaris's group was kind enough to draw me up this little thing because i 534 00:10:31,750 --> 00:10:31,760 draw me up this little thing because i 535 00:10:31,760 --> 00:10:33,509 draw me up this little thing because i couldn't find one usually you try to 536 00:10:33,509 --> 00:10:33,519 couldn't find one usually you try to 537 00:10:33,519 --> 00:10:35,110 couldn't find one usually you try to steal stuff from someplace else for 538 00:10:35,110 --> 00:10:35,120 steal stuff from someplace else for 539 00:10:35,120 --> 00:10:37,509 steal stuff from someplace else for these to save yourself work but 540 00:10:37,509 --> 00:10:37,519 these to save yourself work but 541 00:10:37,519 --> 00:10:38,630 these to save yourself work but uh 542 00:10:38,630 --> 00:10:38,640 uh 543 00:10:38,640 --> 00:10:40,550 uh we couldn't get by with it so we had to 544 00:10:40,550 --> 00:10:40,560 we couldn't get by with it so we had to 545 00:10:40,560 --> 00:10:41,829 we couldn't get by with it so we had to make one 546 00:10:41,829 --> 00:10:41,839 make one 547 00:10:41,839 --> 00:10:44,630 make one and this is a little 548 00:10:44,630 --> 00:10:44,640 and this is a little 549 00:10:44,640 --> 00:10:47,670 and this is a little drawing of a joint to illustrate 550 00:10:47,670 --> 00:10:47,680 drawing of a joint to illustrate 551 00:10:47,680 --> 00:10:50,230 drawing of a joint to illustrate the clearance hole gaps on fasteners and 552 00:10:50,230 --> 00:10:50,240 the clearance hole gaps on fasteners and 553 00:10:50,240 --> 00:10:53,190 the clearance hole gaps on fasteners and where it gets you in trouble 554 00:10:53,190 --> 00:10:53,200 where it gets you in trouble 555 00:10:53,200 --> 00:10:55,750 where it gets you in trouble now this happens a lot 556 00:10:55,750 --> 00:10:55,760 now this happens a lot 557 00:10:55,760 --> 00:10:58,389 now this happens a lot i'll go to this one over here to maybe a 558 00:10:58,389 --> 00:10:58,399 i'll go to this one over here to maybe a 559 00:10:58,399 --> 00:11:00,310 i'll go to this one over here to maybe a little clearer this happens a lot where 560 00:11:00,310 --> 00:11:00,320 little clearer this happens a lot where 561 00:11:00,320 --> 00:11:02,710 little clearer this happens a lot where you have two pieces 562 00:11:02,710 --> 00:11:02,720 you have two pieces 563 00:11:02,720 --> 00:11:03,990 you have two pieces that 564 00:11:03,990 --> 00:11:04,000 that 565 00:11:04,000 --> 00:11:06,150 that one place makes one piece and somebody 566 00:11:06,150 --> 00:11:06,160 one place makes one piece and somebody 567 00:11:06,160 --> 00:11:07,990 one place makes one piece and somebody else makes the other one then you bring 568 00:11:07,990 --> 00:11:08,000 else makes the other one then you bring 569 00:11:08,000 --> 00:11:09,110 else makes the other one then you bring them back and you try to put them 570 00:11:09,110 --> 00:11:09,120 them back and you try to put them 571 00:11:09,120 --> 00:11:10,550 them back and you try to put them together 572 00:11:10,550 --> 00:11:10,560 together 573 00:11:10,560 --> 00:11:13,110 together and this is what you get now these are 574 00:11:13,110 --> 00:11:13,120 and this is what you get now these are 575 00:11:13,120 --> 00:11:14,949 and this is what you get now these are the different gaps see 576 00:11:14,949 --> 00:11:14,959 the different gaps see 577 00:11:14,959 --> 00:11:18,550 the different gaps see see here we have no gap on this 578 00:11:18,550 --> 00:11:18,560 see here we have no gap on this 579 00:11:18,560 --> 00:11:20,470 see here we have no gap on this but look what we got up here and look 580 00:11:20,470 --> 00:11:20,480 but look what we got up here and look 581 00:11:20,480 --> 00:11:22,550 but look what we got up here and look what we got here 582 00:11:22,550 --> 00:11:22,560 what we got here 583 00:11:22,560 --> 00:11:25,030 what we got here so if you pull on that 584 00:11:25,030 --> 00:11:25,040 so if you pull on that 585 00:11:25,040 --> 00:11:26,630 so if you pull on that the only way 586 00:11:26,630 --> 00:11:26,640 the only way 587 00:11:26,640 --> 00:11:30,150 the only way that these other fasteners can load up 588 00:11:30,150 --> 00:11:30,160 that these other fasteners can load up 589 00:11:30,160 --> 00:11:31,910 that these other fasteners can load up like for instance here 590 00:11:31,910 --> 00:11:31,920 like for instance here 591 00:11:31,920 --> 00:11:33,910 like for instance here since that one is up against the the 592 00:11:33,910 --> 00:11:33,920 since that one is up against the the 593 00:11:33,920 --> 00:11:35,750 since that one is up against the the wall right now 594 00:11:35,750 --> 00:11:35,760 wall right now 595 00:11:35,760 --> 00:11:38,069 wall right now in order for this one to load up 596 00:11:38,069 --> 00:11:38,079 in order for this one to load up 597 00:11:38,079 --> 00:11:40,790 in order for this one to load up the hole has to elongate on here for 598 00:11:40,790 --> 00:11:40,800 the hole has to elongate on here for 599 00:11:40,800 --> 00:11:43,190 the hole has to elongate on here for that one to load up so 600 00:11:43,190 --> 00:11:43,200 that one to load up so 601 00:11:43,200 --> 00:11:46,310 that one to load up so so this is why that in a 602 00:11:46,310 --> 00:11:46,320 so this is why that in a 603 00:11:46,320 --> 00:11:49,829 so this is why that in a real shear applications critical design 604 00:11:49,829 --> 00:11:49,839 real shear applications critical design 605 00:11:49,839 --> 00:11:51,829 real shear applications critical design you should match drill 606 00:11:51,829 --> 00:11:51,839 you should match drill 607 00:11:51,839 --> 00:11:53,990 you should match drill and this is what the aerospace companies 608 00:11:53,990 --> 00:11:54,000 and this is what the aerospace companies 609 00:11:54,000 --> 00:11:56,870 and this is what the aerospace companies do they'll take the pieces 610 00:11:56,870 --> 00:11:56,880 do they'll take the pieces 611 00:11:56,880 --> 00:11:59,990 do they'll take the pieces they'll have a pilot hole in one 612 00:11:59,990 --> 00:12:00,000 they'll have a pilot hole in one 613 00:12:00,000 --> 00:12:01,990 they'll have a pilot hole in one which is a smaller diameter hole than 614 00:12:01,990 --> 00:12:02,000 which is a smaller diameter hole than 615 00:12:02,000 --> 00:12:03,990 which is a smaller diameter hole than the the hole that needs to be in it at 616 00:12:03,990 --> 00:12:04,000 the the hole that needs to be in it at 617 00:12:04,000 --> 00:12:05,269 the the hole that needs to be in it at the end 618 00:12:05,269 --> 00:12:05,279 the end 619 00:12:05,279 --> 00:12:07,430 the end they will clamp them together then they 620 00:12:07,430 --> 00:12:07,440 they will clamp them together then they 621 00:12:07,440 --> 00:12:09,590 they will clamp them together then they will use that pilot hole 622 00:12:09,590 --> 00:12:09,600 will use that pilot hole 623 00:12:09,600 --> 00:12:12,550 will use that pilot hole to go in with the proper size drill and 624 00:12:12,550 --> 00:12:12,560 to go in with the proper size drill and 625 00:12:12,560 --> 00:12:14,550 to go in with the proper size drill and drill the hole all the way through both 626 00:12:14,550 --> 00:12:14,560 drill the hole all the way through both 627 00:12:14,560 --> 00:12:17,110 drill the hole all the way through both pieces so that it matches perfectly 628 00:12:17,110 --> 00:12:17,120 pieces so that it matches perfectly 629 00:12:17,120 --> 00:12:19,350 pieces so that it matches perfectly drilled with the same drill 630 00:12:19,350 --> 00:12:19,360 drilled with the same drill 631 00:12:19,360 --> 00:12:21,269 drilled with the same drill and then you put it together and you 632 00:12:21,269 --> 00:12:21,279 and then you put it together and you 633 00:12:21,279 --> 00:12:31,430 and then you put it together and you don't have this problem 634 00:12:31,430 --> 00:12:31,440 635 00:12:31,440 --> 00:12:33,670 now here here's another one that 636 00:12:33,670 --> 00:12:33,680 now here here's another one that 637 00:12:33,680 --> 00:12:35,750 now here here's another one that we can run into trouble on is mixing of 638 00:12:35,750 --> 00:12:35,760 we can run into trouble on is mixing of 639 00:12:35,760 --> 00:12:38,870 we can run into trouble on is mixing of the thread and material types and this 640 00:12:38,870 --> 00:12:38,880 the thread and material types and this 641 00:12:38,880 --> 00:12:41,430 the thread and material types and this happens in designs sometimes 642 00:12:41,430 --> 00:12:41,440 happens in designs sometimes 643 00:12:41,440 --> 00:12:42,710 happens in designs sometimes because 644 00:12:42,710 --> 00:12:42,720 because 645 00:12:42,720 --> 00:12:45,190 because you can have say 300 series stainless 646 00:12:45,190 --> 00:12:45,200 you can have say 300 series stainless 647 00:12:45,200 --> 00:12:46,870 you can have say 300 series stainless steel fasteners 648 00:12:46,870 --> 00:12:46,880 steel fasteners 649 00:12:46,880 --> 00:12:49,269 steel fasteners and you can have a286 stainless steel 650 00:12:49,269 --> 00:12:49,279 and you can have a286 stainless steel 651 00:12:49,279 --> 00:12:51,590 and you can have a286 stainless steel fasteners and you look at them 652 00:12:51,590 --> 00:12:51,600 fasteners and you look at them 653 00:12:51,600 --> 00:12:53,430 fasteners and you look at them they look alike 654 00:12:53,430 --> 00:12:53,440 they look alike 655 00:12:53,440 --> 00:12:55,829 they look alike the one has a strength of usually of 160 656 00:12:55,829 --> 00:12:55,839 the one has a strength of usually of 160 657 00:12:55,839 --> 00:12:58,470 the one has a strength of usually of 160 and the other one has a strength of 70. 658 00:12:58,470 --> 00:12:58,480 and the other one has a strength of 70. 659 00:12:58,480 --> 00:13:01,990 and the other one has a strength of 70. so you can get in trouble with it so 660 00:13:01,990 --> 00:13:02,000 so you can get in trouble with it so 661 00:13:02,000 --> 00:13:04,310 so you can get in trouble with it so if the different sizes 662 00:13:04,310 --> 00:13:04,320 if the different sizes 663 00:13:04,320 --> 00:13:07,509 if the different sizes have fine or coarse threads on the same 664 00:13:07,509 --> 00:13:07,519 have fine or coarse threads on the same 665 00:13:07,519 --> 00:13:09,430 have fine or coarse threads on the same diameters or i mean if you have them 666 00:13:09,430 --> 00:13:09,440 diameters or i mean if you have them 667 00:13:09,440 --> 00:13:11,590 diameters or i mean if you have them with the same diameters with the 668 00:13:11,590 --> 00:13:11,600 with the same diameters with the 669 00:13:11,600 --> 00:13:13,829 with the same diameters with the finer coarse threads or metric threads 670 00:13:13,829 --> 00:13:13,839 finer coarse threads or metric threads 671 00:13:13,839 --> 00:13:16,230 finer coarse threads or metric threads then you're in real trouble because 672 00:13:16,230 --> 00:13:16,240 then you're in real trouble because 673 00:13:16,240 --> 00:13:18,230 then you're in real trouble because to a mechanic all these fasteners look 674 00:13:18,230 --> 00:13:18,240 to a mechanic all these fasteners look 675 00:13:18,240 --> 00:13:19,750 to a mechanic all these fasteners look alike 676 00:13:19,750 --> 00:13:19,760 alike 677 00:13:19,760 --> 00:13:22,230 alike and this happened on the cm1 job if i 678 00:13:22,230 --> 00:13:22,240 and this happened on the cm1 job if i 679 00:13:22,240 --> 00:13:24,310 and this happened on the cm1 job if i recall we had one that the guy couldn't 680 00:13:24,310 --> 00:13:24,320 recall we had one that the guy couldn't 681 00:13:24,320 --> 00:13:25,990 recall we had one that the guy couldn't figure out why it wouldn't go in the 682 00:13:25,990 --> 00:13:26,000 figure out why it wouldn't go in the 683 00:13:26,000 --> 00:13:27,750 figure out why it wouldn't go in the hole 684 00:13:27,750 --> 00:13:27,760 hole 685 00:13:27,760 --> 00:13:29,670 hole and it was a metric 686 00:13:29,670 --> 00:13:29,680 and it was a metric 687 00:13:29,680 --> 00:13:31,350 and it was a metric course 688 00:13:31,350 --> 00:13:31,360 course 689 00:13:31,360 --> 00:13:34,230 course when i had him get a gauge engage it and 690 00:13:34,230 --> 00:13:34,240 when i had him get a gauge engage it and 691 00:13:34,240 --> 00:13:37,110 when i had him get a gauge engage it and we had inch stuff around there too so 692 00:13:37,110 --> 00:13:37,120 we had inch stuff around there too so 693 00:13:37,120 --> 00:13:39,030 we had inch stuff around there too so and and the rest of the metric stuff was 694 00:13:39,030 --> 00:13:39,040 and and the rest of the metric stuff was 695 00:13:39,040 --> 00:13:40,389 and and the rest of the metric stuff was fine thread i think and this one 696 00:13:40,389 --> 00:13:40,399 fine thread i think and this one 697 00:13:40,399 --> 00:13:42,790 fine thread i think and this one happened to be of course so so this is 698 00:13:42,790 --> 00:13:42,800 happened to be of course so so this is 699 00:13:42,800 --> 00:13:44,790 happened to be of course so so this is asking for trouble because if something 700 00:13:44,790 --> 00:13:44,800 asking for trouble because if something 701 00:13:44,800 --> 00:13:46,069 asking for trouble because if something won't fit somebody's going to try to 702 00:13:46,069 --> 00:13:46,079 won't fit somebody's going to try to 703 00:13:46,079 --> 00:13:48,870 won't fit somebody's going to try to make it fit and they put it together 704 00:13:48,870 --> 00:13:48,880 make it fit and they put it together 705 00:13:48,880 --> 00:13:50,150 make it fit and they put it together now 706 00:13:50,150 --> 00:13:50,160 now 707 00:13:50,160 --> 00:13:53,829 now we covered the different strength levels 708 00:13:53,829 --> 00:13:53,839 we covered the different strength levels 709 00:13:53,839 --> 00:13:57,430 we covered the different strength levels and the fact that 300 series and a286 710 00:13:57,430 --> 00:13:57,440 and the fact that 300 series and a286 711 00:13:57,440 --> 00:13:59,110 and the fact that 300 series and a286 look alike 712 00:13:59,110 --> 00:13:59,120 look alike 713 00:13:59,120 --> 00:14:02,710 look alike stainless steels look alike and even 714 00:14:02,710 --> 00:14:02,720 stainless steels look alike and even 715 00:14:02,720 --> 00:14:06,150 stainless steels look alike and even different platings on materials can be 716 00:14:06,150 --> 00:14:06,160 different platings on materials can be 717 00:14:06,160 --> 00:14:08,790 different platings on materials can be dyed to where they 718 00:14:08,790 --> 00:14:08,800 dyed to where they 719 00:14:08,800 --> 00:14:11,670 dyed to where they they look alike 720 00:14:11,670 --> 00:14:11,680 721 00:14:11,680 --> 00:14:13,430 so next we go to the selection and 722 00:14:13,430 --> 00:14:13,440 so next we go to the selection and 723 00:14:13,440 --> 00:14:15,430 so next we go to the selection and positioning of the washer 724 00:14:15,430 --> 00:14:15,440 positioning of the washer 725 00:14:15,440 --> 00:14:17,509 positioning of the washer and you've got to pick washers that are 726 00:14:17,509 --> 00:14:17,519 and you've got to pick washers that are 727 00:14:17,519 --> 00:14:19,189 and you've got to pick washers that are large enough to distribute the load 728 00:14:19,189 --> 00:14:19,199 large enough to distribute the load 729 00:14:19,199 --> 00:14:21,269 large enough to distribute the load under the head or the nut 730 00:14:21,269 --> 00:14:21,279 under the head or the nut 731 00:14:21,279 --> 00:14:23,110 under the head or the nut without exceeding the compressive yield 732 00:14:23,110 --> 00:14:23,120 without exceeding the compressive yield 733 00:14:23,120 --> 00:14:25,509 without exceeding the compressive yield strength of the joint material 734 00:14:25,509 --> 00:14:25,519 strength of the joint material 735 00:14:25,519 --> 00:14:27,430 strength of the joint material so uh 736 00:14:27,430 --> 00:14:27,440 so uh 737 00:14:27,440 --> 00:14:29,590 so uh you want a hard washer and a smooth one 738 00:14:29,590 --> 00:14:29,600 you want a hard washer and a smooth one 739 00:14:29,600 --> 00:14:31,189 you want a hard washer and a smooth one so that you can you know what your 740 00:14:31,189 --> 00:14:31,199 so that you can you know what your 741 00:14:31,199 --> 00:14:32,710 so that you can you know what your coefficient of friction 742 00:14:32,710 --> 00:14:32,720 coefficient of friction 743 00:14:32,720 --> 00:14:34,790 coefficient of friction is going to be 744 00:14:34,790 --> 00:14:34,800 is going to be 745 00:14:34,800 --> 00:14:36,949 is going to be and if the internal diameter the washer 746 00:14:36,949 --> 00:14:36,959 and if the internal diameter the washer 747 00:14:36,959 --> 00:14:38,790 and if the internal diameter the washer is much larger than the fastener then 748 00:14:38,790 --> 00:14:38,800 is much larger than the fastener then 749 00:14:38,800 --> 00:14:41,189 is much larger than the fastener then you better try to try to center it 750 00:14:41,189 --> 00:14:41,199 you better try to try to center it 751 00:14:41,199 --> 00:14:43,110 you better try to try to center it to make sure that they will fit don't do 752 00:14:43,110 --> 00:14:43,120 to make sure that they will fit don't do 753 00:14:43,120 --> 00:14:45,030 to make sure that they will fit don't do one of those deals like i've seen people 754 00:14:45,030 --> 00:14:45,040 one of those deals like i've seen people 755 00:14:45,040 --> 00:14:46,470 one of those deals like i've seen people do before where they stack up a whole 756 00:14:46,470 --> 00:14:46,480 do before where they stack up a whole 757 00:14:46,480 --> 00:14:47,910 do before where they stack up a whole bunch of washers 758 00:14:47,910 --> 00:14:47,920 bunch of washers 759 00:14:47,920 --> 00:14:49,590 bunch of washers and then they got to jiggle them around 760 00:14:49,590 --> 00:14:49,600 and then they got to jiggle them around 761 00:14:49,600 --> 00:14:51,509 and then they got to jiggle them around to get them to fit 762 00:14:51,509 --> 00:14:51,519 to get them to fit 763 00:14:51,519 --> 00:14:52,710 to get them to fit under the head 764 00:14:52,710 --> 00:14:52,720 under the head 765 00:14:52,720 --> 00:14:54,870 under the head and you might wind up with with the 766 00:14:54,870 --> 00:14:54,880 and you might wind up with with the 767 00:14:54,880 --> 00:14:56,230 and you might wind up with with the thing 768 00:14:56,230 --> 00:14:56,240 thing 769 00:14:56,240 --> 00:14:58,069 thing embedding in the material on one side 770 00:14:58,069 --> 00:14:58,079 embedding in the material on one side 771 00:14:58,079 --> 00:15:02,389 embedding in the material on one side and on the other side is hardly loaded 772 00:15:02,389 --> 00:15:02,399 773 00:15:02,399 --> 00:15:05,590 now shear loads on a fastener group 774 00:15:05,590 --> 00:15:05,600 now shear loads on a fastener group 775 00:15:05,600 --> 00:15:08,550 now shear loads on a fastener group this is something that i i gave you 776 00:15:08,550 --> 00:15:08,560 this is something that i i gave you 777 00:15:08,560 --> 00:15:12,069 this is something that i i gave you a lot of verbiage on this to help you go 778 00:15:12,069 --> 00:15:12,079 a lot of verbiage on this to help you go 779 00:15:12,079 --> 00:15:14,550 a lot of verbiage on this to help you go through the stuff on your own 780 00:15:14,550 --> 00:15:14,560 through the stuff on your own 781 00:15:14,560 --> 00:15:17,269 through the stuff on your own and uh so i'll just kind of hit the the 782 00:15:17,269 --> 00:15:17,279 and uh so i'll just kind of hit the the 783 00:15:17,279 --> 00:15:19,590 and uh so i'll just kind of hit the the highlights on this number one on where 784 00:15:19,590 --> 00:15:19,600 highlights on this number one on where 785 00:15:19,600 --> 00:15:21,189 highlights on this number one on where you have a pattern of fasteners the 786 00:15:21,189 --> 00:15:21,199 you have a pattern of fasteners the 787 00:15:21,199 --> 00:15:23,110 you have a pattern of fasteners the first thing you want to do is determine 788 00:15:23,110 --> 00:15:23,120 first thing you want to do is determine 789 00:15:23,120 --> 00:15:25,269 first thing you want to do is determine the centroid of the pattern but pick 790 00:15:25,269 --> 00:15:25,279 the centroid of the pattern but pick 791 00:15:25,279 --> 00:15:27,829 the centroid of the pattern but pick picking x and y axes and using unit 792 00:15:27,829 --> 00:15:27,839 picking x and y axes and using unit 793 00:15:27,839 --> 00:15:29,030 picking x and y axes and using unit areas 794 00:15:29,030 --> 00:15:29,040 areas 795 00:15:29,040 --> 00:15:32,310 areas times its distance to get the centroid 796 00:15:32,310 --> 00:15:32,320 times its distance to get the centroid 797 00:15:32,320 --> 00:15:33,110 times its distance to get the centroid and 798 00:15:33,110 --> 00:15:33,120 and 799 00:15:33,120 --> 00:15:34,949 and although it's not a good idea to have 800 00:15:34,949 --> 00:15:34,959 although it's not a good idea to have 801 00:15:34,959 --> 00:15:37,430 although it's not a good idea to have fasteners of a different diameter 802 00:15:37,430 --> 00:15:37,440 fasteners of a different diameter 803 00:15:37,440 --> 00:15:39,110 fasteners of a different diameter you can 804 00:15:39,110 --> 00:15:39,120 you can 805 00:15:39,120 --> 00:15:41,749 you can use them in this type of analysis by 806 00:15:41,749 --> 00:15:41,759 use them in this type of analysis by 807 00:15:41,759 --> 00:15:43,829 use them in this type of analysis by ratioing the diameters 808 00:15:43,829 --> 00:15:43,839 ratioing the diameters 809 00:15:43,839 --> 00:15:46,310 ratioing the diameters for instance the one i gave here if i 810 00:15:46,310 --> 00:15:46,320 for instance the one i gave here if i 811 00:15:46,320 --> 00:15:48,550 for instance the one i gave here if i had eight bolts of a 12-volt pattern 812 00:15:48,550 --> 00:15:48,560 had eight bolts of a 12-volt pattern 813 00:15:48,560 --> 00:15:50,230 had eight bolts of a 12-volt pattern that were three-eighths and the other 814 00:15:50,230 --> 00:15:50,240 that were three-eighths and the other 815 00:15:50,240 --> 00:15:52,829 that were three-eighths and the other four or five-sixteenths 816 00:15:52,829 --> 00:15:52,839 four or five-sixteenths 817 00:15:52,839 --> 00:15:56,949 four or five-sixteenths uh you can ratio the shank diameters and 818 00:15:56,949 --> 00:15:56,959 uh you can ratio the shank diameters and 819 00:15:56,959 --> 00:15:58,550 uh you can ratio the shank diameters and you use 820 00:15:58,550 --> 00:15:58,560 you use 821 00:15:58,560 --> 00:16:00,230 you use one 822 00:16:00,230 --> 00:16:00,240 one 823 00:16:00,240 --> 00:16:02,870 one for the one that you have the most of 824 00:16:02,870 --> 00:16:02,880 for the one that you have the most of 825 00:16:02,880 --> 00:16:05,269 for the one that you have the most of and use the the stress ratios then to 826 00:16:05,269 --> 00:16:05,279 and use the the stress ratios then to 827 00:16:05,279 --> 00:16:07,350 and use the the stress ratios then to give you a factor for the other one to 828 00:16:07,350 --> 00:16:07,360 give you a factor for the other one to 829 00:16:07,360 --> 00:16:08,389 give you a factor for the other one to use 830 00:16:08,389 --> 00:16:08,399 use 831 00:16:08,399 --> 00:16:10,550 use this way you can calculate 832 00:16:10,550 --> 00:16:10,560 this way you can calculate 833 00:16:10,560 --> 00:16:11,430 this way you can calculate the 834 00:16:11,430 --> 00:16:11,440 the 835 00:16:11,440 --> 00:16:12,710 the the pattern 836 00:16:12,710 --> 00:16:12,720 the pattern 837 00:16:12,720 --> 00:16:15,990 the pattern cg and get the loads on it 838 00:16:15,990 --> 00:16:16,000 cg and get the loads on it 839 00:16:16,000 --> 00:16:18,629 cg and get the loads on it okay now 840 00:16:18,629 --> 00:16:18,639 841 00:16:18,639 --> 00:16:19,749 uh 842 00:16:19,749 --> 00:16:19,759 uh 843 00:16:19,759 --> 00:16:21,350 uh in a lot of cases you'll have a 844 00:16:21,350 --> 00:16:21,360 in a lot of cases you'll have a 845 00:16:21,360 --> 00:16:24,870 in a lot of cases you'll have a symmetrical pattern so you're okay 846 00:16:24,870 --> 00:16:24,880 symmetrical pattern so you're okay 847 00:16:24,880 --> 00:16:26,230 symmetrical pattern so you're okay and uh 848 00:16:26,230 --> 00:16:26,240 and uh 849 00:16:26,240 --> 00:16:27,030 and uh but 850 00:16:27,030 --> 00:16:27,040 but 851 00:16:27,040 --> 00:16:29,430 but after you find the the centroid then you 852 00:16:29,430 --> 00:16:29,440 after you find the the centroid then you 853 00:16:29,440 --> 00:16:32,150 after you find the the centroid then you can get these sigma r squares for the 854 00:16:32,150 --> 00:16:32,160 can get these sigma r squares for the 855 00:16:32,160 --> 00:16:35,189 can get these sigma r squares for the for the fasteners which will give you an 856 00:16:35,189 --> 00:16:35,199 for the fasteners which will give you an 857 00:16:35,199 --> 00:16:37,749 for the fasteners which will give you an equivalent moment of inertia if you will 858 00:16:37,749 --> 00:16:37,759 equivalent moment of inertia if you will 859 00:16:37,759 --> 00:16:39,829 equivalent moment of inertia if you will like like calculating bending stresses 860 00:16:39,829 --> 00:16:39,839 like like calculating bending stresses 861 00:16:39,839 --> 00:16:40,790 like like calculating bending stresses so 862 00:16:40,790 --> 00:16:40,800 so 863 00:16:40,800 --> 00:16:42,949 so uh we can move over to the figure and i 864 00:16:42,949 --> 00:16:42,959 uh we can move over to the figure and i 865 00:16:42,959 --> 00:16:45,749 uh we can move over to the figure and i think i can talk you through that better 866 00:16:45,749 --> 00:16:45,759 think i can talk you through that better 867 00:16:45,759 --> 00:16:48,710 think i can talk you through that better uh here is a a bracket 868 00:16:48,710 --> 00:16:48,720 uh here is a a bracket 869 00:16:48,720 --> 00:16:52,069 uh here is a a bracket that has a an eccentric load on it here 870 00:16:52,069 --> 00:16:52,079 that has a an eccentric load on it here 871 00:16:52,079 --> 00:16:53,590 that has a an eccentric load on it here are 872 00:16:53,590 --> 00:16:53,600 are 873 00:16:53,600 --> 00:16:55,590 are okay now to get 874 00:16:55,590 --> 00:16:55,600 okay now to get 875 00:16:55,600 --> 00:16:57,350 okay now to get and it's loaded just in shear we're not 876 00:16:57,350 --> 00:16:57,360 and it's loaded just in shear we're not 877 00:16:57,360 --> 00:16:59,590 and it's loaded just in shear we're not putting any tension on it 878 00:16:59,590 --> 00:16:59,600 putting any tension on it 879 00:16:59,600 --> 00:17:00,790 putting any tension on it so 880 00:17:00,790 --> 00:17:00,800 so 881 00:17:00,800 --> 00:17:03,829 so we have to transfer that to the cg of 882 00:17:03,829 --> 00:17:03,839 we have to transfer that to the cg of 883 00:17:03,839 --> 00:17:06,470 we have to transfer that to the cg of course remember in strength of materials 884 00:17:06,470 --> 00:17:06,480 course remember in strength of materials 885 00:17:06,480 --> 00:17:08,230 course remember in strength of materials you transfer a load 886 00:17:08,230 --> 00:17:08,240 you transfer a load 887 00:17:08,240 --> 00:17:10,949 you transfer a load to the cg you have a 888 00:17:10,949 --> 00:17:10,959 to the cg you have a 889 00:17:10,959 --> 00:17:13,350 to the cg you have a direct load and a moment is what you 890 00:17:13,350 --> 00:17:13,360 direct load and a moment is what you 891 00:17:13,360 --> 00:17:14,789 direct load and a moment is what you replace it with 892 00:17:14,789 --> 00:17:14,799 replace it with 893 00:17:14,799 --> 00:17:15,590 replace it with so 894 00:17:15,590 --> 00:17:15,600 so 895 00:17:15,600 --> 00:17:18,230 so so you have this is your direct load is 896 00:17:18,230 --> 00:17:18,240 so you have this is your direct load is 897 00:17:18,240 --> 00:17:19,990 so you have this is your direct load is just taking r and divide it by the 898 00:17:19,990 --> 00:17:20,000 just taking r and divide it by the 899 00:17:20,000 --> 00:17:21,990 just taking r and divide it by the number of fasteners that gives you a 900 00:17:21,990 --> 00:17:22,000 number of fasteners that gives you a 901 00:17:22,000 --> 00:17:23,590 number of fasteners that gives you a load there 902 00:17:23,590 --> 00:17:23,600 load there 903 00:17:23,600 --> 00:17:25,750 load there now you get a moment 904 00:17:25,750 --> 00:17:25,760 now you get a moment 905 00:17:25,760 --> 00:17:28,309 now you get a moment r times this value e 906 00:17:28,309 --> 00:17:28,319 r times this value e 907 00:17:28,319 --> 00:17:30,789 r times this value e which you have to react now the way that 908 00:17:30,789 --> 00:17:30,799 which you have to react now the way that 909 00:17:30,799 --> 00:17:32,870 which you have to react now the way that you react that 910 00:17:32,870 --> 00:17:32,880 you react that 911 00:17:32,880 --> 00:17:35,909 you react that you take these r values 912 00:17:35,909 --> 00:17:35,919 you take these r values 913 00:17:35,919 --> 00:17:37,510 you take these r values which is the distance this is the 914 00:17:37,510 --> 00:17:37,520 which is the distance this is the 915 00:17:37,520 --> 00:17:39,270 which is the distance this is the centroid since it's a symmetrical 916 00:17:39,270 --> 00:17:39,280 centroid since it's a symmetrical 917 00:17:39,280 --> 00:17:40,230 centroid since it's a symmetrical pattern 918 00:17:40,230 --> 00:17:40,240 pattern 919 00:17:40,240 --> 00:17:43,190 pattern so you have four r values measured here 920 00:17:43,190 --> 00:17:43,200 so you have four r values measured here 921 00:17:43,200 --> 00:17:45,270 so you have four r values measured here here here and here 922 00:17:45,270 --> 00:17:45,280 here here and here 923 00:17:45,280 --> 00:17:46,390 here here and here that are the same 924 00:17:46,390 --> 00:17:46,400 that are the same 925 00:17:46,400 --> 00:17:47,909 that are the same and then you have four more that are the 926 00:17:47,909 --> 00:17:47,919 and then you have four more that are the 927 00:17:47,919 --> 00:17:50,549 and then you have four more that are the same from here to here from here to here 928 00:17:50,549 --> 00:17:50,559 same from here to here from here to here 929 00:17:50,559 --> 00:17:53,190 same from here to here from here to here up to there and down to here so now you 930 00:17:53,190 --> 00:17:53,200 up to there and down to here so now you 931 00:17:53,200 --> 00:17:55,270 up to there and down to here so now you take those and add them up so you have 932 00:17:55,270 --> 00:17:55,280 take those and add them up so you have 933 00:17:55,280 --> 00:17:59,110 take those and add them up so you have four times r one squared 934 00:17:59,110 --> 00:17:59,120 four times r one squared 935 00:17:59,120 --> 00:18:02,950 four times r one squared plus 4 times r2 squared and that gives 936 00:18:02,950 --> 00:18:02,960 plus 4 times r2 squared and that gives 937 00:18:02,960 --> 00:18:05,750 plus 4 times r2 squared and that gives you your equivalent moment of inertia if 938 00:18:05,750 --> 00:18:05,760 you your equivalent moment of inertia if 939 00:18:05,760 --> 00:18:07,270 you your equivalent moment of inertia if you will 940 00:18:07,270 --> 00:18:07,280 you will 941 00:18:07,280 --> 00:18:09,990 you will then you can find a load on the fastener 942 00:18:09,990 --> 00:18:10,000 then you can find a load on the fastener 943 00:18:10,000 --> 00:18:12,150 then you can find a load on the fastener by taking the moment 944 00:18:12,150 --> 00:18:12,160 by taking the moment 945 00:18:12,160 --> 00:18:13,270 by taking the moment times 946 00:18:13,270 --> 00:18:13,280 times 947 00:18:13,280 --> 00:18:14,390 times the 948 00:18:14,390 --> 00:18:14,400 the 949 00:18:14,400 --> 00:18:18,310 the radius to the one that is farthest away 950 00:18:18,310 --> 00:18:18,320 radius to the one that is farthest away 951 00:18:18,320 --> 00:18:22,310 radius to the one that is farthest away and that then over the sigma r squared 952 00:18:22,310 --> 00:18:22,320 and that then over the sigma r squared 953 00:18:22,320 --> 00:18:25,510 and that then over the sigma r squared value that you calculated using uh those 954 00:18:25,510 --> 00:18:25,520 value that you calculated using uh those 955 00:18:25,520 --> 00:18:26,549 value that you calculated using uh those values 956 00:18:26,549 --> 00:18:26,559 values 957 00:18:26,559 --> 00:18:28,710 values and you come up with another load now 958 00:18:28,710 --> 00:18:28,720 and you come up with another load now 959 00:18:28,720 --> 00:18:30,310 and you come up with another load now you take those two 960 00:18:30,310 --> 00:18:30,320 you take those two 961 00:18:30,320 --> 00:18:32,870 you take those two since they're both in the shear plane 962 00:18:32,870 --> 00:18:32,880 since they're both in the shear plane 963 00:18:32,880 --> 00:18:34,950 since they're both in the shear plane you combine them vectorially to get a 964 00:18:34,950 --> 00:18:34,960 you combine them vectorially to get a 965 00:18:34,960 --> 00:18:37,350 you combine them vectorially to get a resultant load p 966 00:18:37,350 --> 00:18:37,360 resultant load p 967 00:18:37,360 --> 00:18:40,470 resultant load p for a total shear load on the fastener 968 00:18:40,470 --> 00:18:40,480 for a total shear load on the fastener 969 00:18:40,480 --> 00:18:42,470 for a total shear load on the fastener then of course that takes care of the 970 00:18:42,470 --> 00:18:42,480 then of course that takes care of the 971 00:18:42,480 --> 00:18:45,270 then of course that takes care of the the shear loads 972 00:18:45,270 --> 00:18:45,280 the shear loads 973 00:18:45,280 --> 00:18:48,470 the shear loads now if if you look at this value this 974 00:18:48,470 --> 00:18:48,480 now if if you look at this value this 975 00:18:48,480 --> 00:18:50,630 now if if you look at this value this also would correspond to like a 976 00:18:50,630 --> 00:18:50,640 also would correspond to like a 977 00:18:50,640 --> 00:18:53,270 also would correspond to like a torsional formula the tr over j in which 978 00:18:53,270 --> 00:18:53,280 torsional formula the tr over j in which 979 00:18:53,280 --> 00:18:56,870 torsional formula the tr over j in which the sigma sigma r squared is the r sub n 980 00:18:56,870 --> 00:18:56,880 the sigma sigma r squared is the r sub n 981 00:18:56,880 --> 00:18:58,630 the sigma sigma r squared is the r sub n squared is the equivalent of a polar 982 00:18:58,630 --> 00:18:58,640 squared is the equivalent of a polar 983 00:18:58,640 --> 00:19:00,870 squared is the equivalent of a polar moment of inertia j 984 00:19:00,870 --> 00:19:00,880 moment of inertia j 985 00:19:00,880 --> 00:19:02,710 moment of inertia j except that the load that you get here 986 00:19:02,710 --> 00:19:02,720 except that the load that you get here 987 00:19:02,720 --> 00:19:05,110 except that the load that you get here is in pounds 988 00:19:05,110 --> 00:19:05,120 is in pounds 989 00:19:05,120 --> 00:19:07,029 is in pounds and so 990 00:19:07,029 --> 00:19:07,039 and so 991 00:19:07,039 --> 00:19:10,390 and so so then later on if we have tension on 992 00:19:10,390 --> 00:19:10,400 so then later on if we have tension on 993 00:19:10,400 --> 00:19:12,230 so then later on if we have tension on on something like this 994 00:19:12,230 --> 00:19:12,240 on something like this 995 00:19:12,240 --> 00:19:15,029 on something like this we can combine it 996 00:19:15,029 --> 00:19:15,039 we can combine it 997 00:19:15,039 --> 00:19:17,830 we can combine it and get the total load 998 00:19:17,830 --> 00:19:17,840 and get the total load 999 00:19:17,840 --> 00:19:19,669 and get the total load using stress ratios 1000 00:19:19,669 --> 00:19:19,679 using stress ratios 1001 00:19:19,679 --> 00:19:21,430 using stress ratios now on edge distance and fastener 1002 00:19:21,430 --> 00:19:21,440 now on edge distance and fastener 1003 00:19:21,440 --> 00:19:22,789 now on edge distance and fastener spacing this is something that's 1004 00:19:22,789 --> 00:19:22,799 spacing this is something that's 1005 00:19:22,799 --> 00:19:24,390 spacing this is something that's violated a lot 1006 00:19:24,390 --> 00:19:24,400 violated a lot 1007 00:19:24,400 --> 00:19:27,029 violated a lot in fact we put out designs around here 1008 00:19:27,029 --> 00:19:27,039 in fact we put out designs around here 1009 00:19:27,039 --> 00:19:28,390 in fact we put out designs around here before 1010 00:19:28,390 --> 00:19:28,400 before 1011 00:19:28,400 --> 00:19:29,590 before that 1012 00:19:29,590 --> 00:19:29,600 that 1013 00:19:29,600 --> 00:19:31,110 that i have 1014 00:19:31,110 --> 00:19:31,120 i have 1015 00:19:31,120 --> 00:19:33,110 i have been very disappointed with because 1016 00:19:33,110 --> 00:19:33,120 been very disappointed with because 1017 00:19:33,120 --> 00:19:34,150 been very disappointed with because somebody 1018 00:19:34,150 --> 00:19:34,160 somebody 1019 00:19:34,160 --> 00:19:36,830 somebody used practically no edge distance on 1020 00:19:36,830 --> 00:19:36,840 used practically no edge distance on 1021 00:19:36,840 --> 00:19:39,669 used practically no edge distance on stuff we want we won't mention any names 1022 00:19:39,669 --> 00:19:39,679 stuff we want we won't mention any names 1023 00:19:39,679 --> 00:19:41,990 stuff we want we won't mention any names but ron knows a guy that 1024 00:19:41,990 --> 00:19:42,000 but ron knows a guy that 1025 00:19:42,000 --> 00:19:44,470 but ron knows a guy that did this a few times on me 1026 00:19:44,470 --> 00:19:44,480 did this a few times on me 1027 00:19:44,480 --> 00:19:46,630 did this a few times on me but uh 1028 00:19:46,630 --> 00:19:46,640 but uh 1029 00:19:46,640 --> 00:19:48,230 but uh here is the 1030 00:19:48,230 --> 00:19:48,240 here is the 1031 00:19:48,240 --> 00:19:51,029 here is the edge distance and fastener spacing and 1032 00:19:51,029 --> 00:19:51,039 edge distance and fastener spacing and 1033 00:19:51,039 --> 00:19:54,390 edge distance and fastener spacing and these are nominal ones so so this is 1034 00:19:54,390 --> 00:19:54,400 these are nominal ones so so this is 1035 00:19:54,400 --> 00:19:57,190 these are nominal ones so so this is kind of what you shoot for 2d nominal 1036 00:19:57,190 --> 00:19:57,200 kind of what you shoot for 2d nominal 1037 00:19:57,200 --> 00:19:59,990 kind of what you shoot for 2d nominal where d is the diameter of the fastener 1038 00:19:59,990 --> 00:20:00,000 where d is the diameter of the fastener 1039 00:20:00,000 --> 00:20:04,230 where d is the diameter of the fastener 4d spacing between fasteners 1040 00:20:04,230 --> 00:20:04,240 4d spacing between fasteners 1041 00:20:04,240 --> 00:20:07,830 4d spacing between fasteners and the aircraft companies usually use a 1042 00:20:07,830 --> 00:20:07,840 and the aircraft companies usually use a 1043 00:20:07,840 --> 00:20:10,710 and the aircraft companies usually use a 2d plus 30 thousandths on their stuff 1044 00:20:10,710 --> 00:20:10,720 2d plus 30 thousandths on their stuff 1045 00:20:10,720 --> 00:20:12,710 2d plus 30 thousandths on their stuff just to give you just a little more edge 1046 00:20:12,710 --> 00:20:12,720 just to give you just a little more edge 1047 00:20:12,720 --> 00:20:15,029 just to give you just a little more edge distance in case you run into a problem 1048 00:20:15,029 --> 00:20:15,039 distance in case you run into a problem 1049 00:20:15,039 --> 00:20:16,149 distance in case you run into a problem now 1050 00:20:16,149 --> 00:20:16,159 now 1051 00:20:16,159 --> 00:20:18,230 now one of the things that questions might 1052 00:20:18,230 --> 00:20:18,240 one of the things that questions might 1053 00:20:18,240 --> 00:20:21,190 one of the things that questions might be asked well if you have a shearer lug 1054 00:20:21,190 --> 00:20:21,200 be asked well if you have a shearer lug 1055 00:20:21,200 --> 00:20:23,110 be asked well if you have a shearer lug it doesn't have 2d 1056 00:20:23,110 --> 00:20:23,120 it doesn't have 2d 1057 00:20:23,120 --> 00:20:24,710 it doesn't have 2d no they're custom designs because 1058 00:20:24,710 --> 00:20:24,720 no they're custom designs because 1059 00:20:24,720 --> 00:20:26,710 no they're custom designs because they're usually pretty thick and you go 1060 00:20:26,710 --> 00:20:26,720 they're usually pretty thick and you go 1061 00:20:26,720 --> 00:20:28,789 they're usually pretty thick and you go in and calculate 1062 00:20:28,789 --> 00:20:28,799 in and calculate 1063 00:20:28,799 --> 00:20:31,110 in and calculate hoop tension and shear tear out and that 1064 00:20:31,110 --> 00:20:31,120 hoop tension and shear tear out and that 1065 00:20:31,120 --> 00:20:33,510 hoop tension and shear tear out and that types of things on a lug 1066 00:20:33,510 --> 00:20:33,520 types of things on a lug 1067 00:20:33,520 --> 00:20:34,789 types of things on a lug and 1068 00:20:34,789 --> 00:20:34,799 and 1069 00:20:34,799 --> 00:20:37,750 and that one is covered 1070 00:20:37,750 --> 00:20:37,760 that one is covered 1071 00:20:37,760 --> 00:20:40,310 that one is covered uh i covered it in that 1072 00:20:40,310 --> 00:20:40,320 uh i covered it in that 1073 00:20:40,320 --> 00:20:42,149 uh i covered it in that the chapter i wrote for that textbook 1074 00:20:42,149 --> 00:20:42,159 the chapter i wrote for that textbook 1075 00:20:42,159 --> 00:20:43,909 the chapter i wrote for that textbook that's not out yet because that was on 1076 00:20:43,909 --> 00:20:43,919 that's not out yet because that was on 1077 00:20:43,919 --> 00:20:45,990 that's not out yet because that was on on fasteners and share 1078 00:20:45,990 --> 00:20:46,000 on fasteners and share 1079 00:20:46,000 --> 00:20:49,029 on fasteners and share and shigley and 1080 00:20:49,029 --> 00:20:49,039 and shigley and 1081 00:20:49,039 --> 00:20:53,270 and shigley and a few other people also have uh 1082 00:20:53,270 --> 00:20:53,280 a few other people also have uh 1083 00:20:53,280 --> 00:20:57,110 a few other people also have uh coverage on uh sheer and lug design 1084 00:20:57,110 --> 00:20:57,120 coverage on uh sheer and lug design 1085 00:20:57,120 --> 00:20:58,549 coverage on uh sheer and lug design when i talk about lug you're talking 1086 00:20:58,549 --> 00:20:58,559 when i talk about lug you're talking 1087 00:20:58,559 --> 00:21:01,350 when i talk about lug you're talking about a crank that is fairly a crank 1088 00:21:01,350 --> 00:21:01,360 about a crank that is fairly a crank 1089 00:21:01,360 --> 00:21:04,070 about a crank that is fairly a crank type thing that is fairly thick so and 1090 00:21:04,070 --> 00:21:04,080 type thing that is fairly thick so and 1091 00:21:04,080 --> 00:21:06,230 type thing that is fairly thick so and usually you have since it's a rotating 1092 00:21:06,230 --> 00:21:06,240 usually you have since it's a rotating 1093 00:21:06,240 --> 00:21:07,190 usually you have since it's a rotating type 1094 00:21:07,190 --> 00:21:07,200 type 1095 00:21:07,200 --> 00:21:09,830 type joint it does not 1096 00:21:09,830 --> 00:21:09,840 joint it does not 1097 00:21:09,840 --> 00:21:12,390 joint it does not have a large edge distance but it's got 1098 00:21:12,390 --> 00:21:12,400 have a large edge distance but it's got 1099 00:21:12,400 --> 00:21:14,470 have a large edge distance but it's got thick walls 1100 00:21:14,470 --> 00:21:14,480 thick walls 1101 00:21:14,480 --> 00:21:16,870 thick walls now here's here's something that i 1102 00:21:16,870 --> 00:21:16,880 now here's here's something that i 1103 00:21:16,880 --> 00:21:19,110 now here's here's something that i use to illustrate one of the other 1104 00:21:19,110 --> 00:21:19,120 use to illustrate one of the other 1105 00:21:19,120 --> 00:21:20,549 use to illustrate one of the other fallacies that we deal with in the 1106 00:21:20,549 --> 00:21:20,559 fallacies that we deal with in the 1107 00:21:20,559 --> 00:21:24,310 fallacies that we deal with in the engineering world 1108 00:21:24,310 --> 00:21:24,320 1109 00:21:24,320 --> 00:21:25,110 the 1110 00:21:25,110 --> 00:21:25,120 the 1111 00:21:25,120 --> 00:21:28,710 the development of bearing stress allowables 1112 00:21:28,710 --> 00:21:28,720 development of bearing stress allowables 1113 00:21:28,720 --> 00:21:30,710 development of bearing stress allowables bearing stresses 1114 00:21:30,710 --> 00:21:30,720 bearing stresses 1115 00:21:30,720 --> 00:21:33,270 bearing stresses uh the the normal way of doing it you 1116 00:21:33,270 --> 00:21:33,280 uh the the normal way of doing it you 1117 00:21:33,280 --> 00:21:34,310 uh the the normal way of doing it you take 1118 00:21:34,310 --> 00:21:34,320 take 1119 00:21:34,320 --> 00:21:36,789 take this sheet is thickness t now this 1120 00:21:36,789 --> 00:21:36,799 this sheet is thickness t now this 1121 00:21:36,799 --> 00:21:38,789 this sheet is thickness t now this represents 1122 00:21:38,789 --> 00:21:38,799 represents 1123 00:21:38,799 --> 00:21:40,310 represents a uh 1124 00:21:40,310 --> 00:21:40,320 a uh 1125 00:21:40,320 --> 00:21:42,310 a uh semicircular there would be a fastener 1126 00:21:42,310 --> 00:21:42,320 semicircular there would be a fastener 1127 00:21:42,320 --> 00:21:44,630 semicircular there would be a fastener fitting in that hole and this represents 1128 00:21:44,630 --> 00:21:44,640 fitting in that hole and this represents 1129 00:21:44,640 --> 00:21:46,870 fitting in that hole and this represents the the lo the way we're 1130 00:21:46,870 --> 00:21:46,880 the the lo the way we're 1131 00:21:46,880 --> 00:21:48,950 the the lo the way we're coming up with the bearing stress here's 1132 00:21:48,950 --> 00:21:48,960 coming up with the bearing stress here's 1133 00:21:48,960 --> 00:21:50,870 coming up with the bearing stress here's what you're actually doing because if 1134 00:21:50,870 --> 00:21:50,880 what you're actually doing because if 1135 00:21:50,880 --> 00:21:53,430 what you're actually doing because if you have a fastener in this hole 1136 00:21:53,430 --> 00:21:53,440 you have a fastener in this hole 1137 00:21:53,440 --> 00:21:54,870 you have a fastener in this hole pushing 1138 00:21:54,870 --> 00:21:54,880 pushing 1139 00:21:54,880 --> 00:21:57,510 pushing the maximum stress is right here 1140 00:21:57,510 --> 00:21:57,520 the maximum stress is right here 1141 00:21:57,520 --> 00:21:59,909 the maximum stress is right here so this represents that maximum stress 1142 00:21:59,909 --> 00:21:59,919 so this represents that maximum stress 1143 00:21:59,919 --> 00:22:01,270 so this represents that maximum stress the here 1144 00:22:01,270 --> 00:22:01,280 the here 1145 00:22:01,280 --> 00:22:03,350 the here it's zero here because you're not 1146 00:22:03,350 --> 00:22:03,360 it's zero here because you're not 1147 00:22:03,360 --> 00:22:05,590 it's zero here because you're not putting any stress on it there 1148 00:22:05,590 --> 00:22:05,600 putting any stress on it there 1149 00:22:05,600 --> 00:22:06,310 putting any stress on it there so 1150 00:22:06,310 --> 00:22:06,320 so 1151 00:22:06,320 --> 00:22:09,990 so what we normally do and uh see uh mil 1152 00:22:09,990 --> 00:22:10,000 what we normally do and uh see uh mil 1153 00:22:10,000 --> 00:22:11,270 what we normally do and uh see uh mil standard 1154 00:22:11,270 --> 00:22:11,280 standard 1155 00:22:11,280 --> 00:22:14,149 standard 1312 which we'll be covering later on in 1156 00:22:14,149 --> 00:22:14,159 1312 which we'll be covering later on in 1157 00:22:14,159 --> 00:22:17,110 1312 which we'll be covering later on in in here gives all the different methods 1158 00:22:17,110 --> 00:22:17,120 in here gives all the different methods 1159 00:22:17,120 --> 00:22:18,630 in here gives all the different methods of testing 1160 00:22:18,630 --> 00:22:18,640 of testing 1161 00:22:18,640 --> 00:22:19,990 of testing of fasteners 1162 00:22:19,990 --> 00:22:20,000 of fasteners 1163 00:22:20,000 --> 00:22:22,870 of fasteners well what they do they put the fastener 1164 00:22:22,870 --> 00:22:22,880 well what they do they put the fastener 1165 00:22:22,880 --> 00:22:25,190 well what they do they put the fastener in the material and they test it to 1166 00:22:25,190 --> 00:22:25,200 in the material and they test it to 1167 00:22:25,200 --> 00:22:26,789 in the material and they test it to failure 1168 00:22:26,789 --> 00:22:26,799 failure 1169 00:22:26,799 --> 00:22:29,029 failure when they get it to failure whatever it 1170 00:22:29,029 --> 00:22:29,039 when they get it to failure whatever it 1171 00:22:29,039 --> 00:22:31,350 when they get it to failure whatever it failed at for a given diameter 1172 00:22:31,350 --> 00:22:31,360 failed at for a given diameter 1173 00:22:31,360 --> 00:22:34,390 failed at for a given diameter they divide it by the diameter times the 1174 00:22:34,390 --> 00:22:34,400 they divide it by the diameter times the 1175 00:22:34,400 --> 00:22:36,070 they divide it by the diameter times the thickness material that's your normal 1176 00:22:36,070 --> 00:22:36,080 thickness material that's your normal 1177 00:22:36,080 --> 00:22:37,590 thickness material that's your normal bearing area 1178 00:22:37,590 --> 00:22:37,600 bearing area 1179 00:22:37,600 --> 00:22:40,230 bearing area and say that's the bearing stress so if 1180 00:22:40,230 --> 00:22:40,240 and say that's the bearing stress so if 1181 00:22:40,240 --> 00:22:42,630 and say that's the bearing stress so if you look in mill handbook five or any of 1182 00:22:42,630 --> 00:22:42,640 you look in mill handbook five or any of 1183 00:22:42,640 --> 00:22:46,149 you look in mill handbook five or any of these books on bearing stress allowables 1184 00:22:46,149 --> 00:22:46,159 these books on bearing stress allowables 1185 00:22:46,159 --> 00:22:48,789 these books on bearing stress allowables you will see that they are way above 1186 00:22:48,789 --> 00:22:48,799 you will see that they are way above 1187 00:22:48,799 --> 00:22:50,710 you will see that they are way above tensile element and tensile yield 1188 00:22:50,710 --> 00:22:50,720 tensile element and tensile yield 1189 00:22:50,720 --> 00:22:53,190 tensile element and tensile yield because they're a fictitious thing 1190 00:22:53,190 --> 00:22:53,200 because they're a fictitious thing 1191 00:22:53,200 --> 00:22:54,549 because they're a fictitious thing what they are 1192 00:22:54,549 --> 00:22:54,559 what they are 1193 00:22:54,559 --> 00:22:57,510 what they are they're a value that has been verified 1194 00:22:57,510 --> 00:22:57,520 they're a value that has been verified 1195 00:22:57,520 --> 00:23:00,630 they're a value that has been verified that you can use it for calculations 1196 00:23:00,630 --> 00:23:00,640 that you can use it for calculations 1197 00:23:00,640 --> 00:23:03,110 that you can use it for calculations and get by with it but it's actually not 1198 00:23:03,110 --> 00:23:03,120 and get by with it but it's actually not 1199 00:23:03,120 --> 00:23:05,750 and get by with it but it's actually not a true stress 1200 00:23:05,750 --> 00:23:05,760 a true stress 1201 00:23:05,760 --> 00:23:08,310 a true stress so if you don't have bearing stress 1202 00:23:08,310 --> 00:23:08,320 so if you don't have bearing stress 1203 00:23:08,320 --> 00:23:10,549 so if you don't have bearing stress allowables for material 1204 00:23:10,549 --> 00:23:10,559 allowables for material 1205 00:23:10,559 --> 00:23:12,070 allowables for material since you see that these are 1206 00:23:12,070 --> 00:23:12,080 since you see that these are 1207 00:23:12,080 --> 00:23:15,990 since you see that these are proportional p1 to the compressive yield 1208 00:23:15,990 --> 00:23:16,000 proportional p1 to the compressive yield 1209 00:23:16,000 --> 00:23:19,669 proportional p1 to the compressive yield equals p2 to the uh 1210 00:23:19,669 --> 00:23:19,679 1211 00:23:19,679 --> 00:23:22,549 ultimate and so on you can come up with 1212 00:23:22,549 --> 00:23:22,559 ultimate and so on you can come up with 1213 00:23:22,559 --> 00:23:23,750 ultimate and so on you can come up with these 1214 00:23:23,750 --> 00:23:23,760 these 1215 00:23:23,760 --> 00:23:27,029 these just by taking one and a half times the 1216 00:23:27,029 --> 00:23:27,039 just by taking one and a half times the 1217 00:23:27,039 --> 00:23:28,630 just by taking one and a half times the compressive yield or compressive 1218 00:23:28,630 --> 00:23:28,640 compressive yield or compressive 1219 00:23:28,640 --> 00:23:30,390 compressive yield or compressive ultimate of the material 1220 00:23:30,390 --> 00:23:30,400 ultimate of the material 1221 00:23:30,400 --> 00:23:33,350 ultimate of the material now that is a conservative figure 1222 00:23:33,350 --> 00:23:33,360 now that is a conservative figure 1223 00:23:33,360 --> 00:23:36,390 now that is a conservative figure and because the actual test value will 1224 00:23:36,390 --> 00:23:36,400 and because the actual test value will 1225 00:23:36,400 --> 00:23:39,430 and because the actual test value will run around 1.7 1226 00:23:39,430 --> 00:23:39,440 run around 1.7 1227 00:23:39,440 --> 00:23:41,190 run around 1.7 for most of these materials but mill 1228 00:23:41,190 --> 00:23:41,200 for most of these materials but mill 1229 00:23:41,200 --> 00:23:44,149 for most of these materials but mill handbook 5 if they didn't test 1230 00:23:44,149 --> 00:23:44,159 handbook 5 if they didn't test 1231 00:23:44,159 --> 00:23:46,230 handbook 5 if they didn't test to get the bearing allowables in a lot 1232 00:23:46,230 --> 00:23:46,240 to get the bearing allowables in a lot 1233 00:23:46,240 --> 00:23:47,669 to get the bearing allowables in a lot of cases they'll just take one and a 1234 00:23:47,669 --> 00:23:47,679 of cases they'll just take one and a 1235 00:23:47,679 --> 00:23:49,750 of cases they'll just take one and a half times the 1236 00:23:49,750 --> 00:23:49,760 half times the 1237 00:23:49,760 --> 00:23:52,149 half times the tensile element or tensile yield and 1238 00:23:52,149 --> 00:23:52,159 tensile element or tensile yield and 1239 00:23:52,159 --> 00:23:53,510 tensile element or tensile yield and slap that in there for the bearing 1240 00:23:53,510 --> 00:23:53,520 slap that in there for the bearing 1241 00:23:53,520 --> 00:24:01,510 slap that in there for the bearing allowable because they know it's safe 1242 00:24:01,510 --> 00:24:01,520 1243 00:24:01,520 --> 00:24:03,190 all right grip length 1244 00:24:03,190 --> 00:24:03,200 all right grip length 1245 00:24:03,200 --> 00:24:05,110 all right grip length and shear head and tension head on 1246 00:24:05,110 --> 00:24:05,120 and shear head and tension head on 1247 00:24:05,120 --> 00:24:07,350 and shear head and tension head on fasteners now 1248 00:24:07,350 --> 00:24:07,360 fasteners now 1249 00:24:07,360 --> 00:24:11,350 fasteners now grip length is a very critical thing 1250 00:24:11,350 --> 00:24:11,360 grip length is a very critical thing 1251 00:24:11,360 --> 00:24:13,990 grip length is a very critical thing for shear design because that is the 1252 00:24:13,990 --> 00:24:14,000 for shear design because that is the 1253 00:24:14,000 --> 00:24:17,190 for shear design because that is the length of the unthreaded portion 1254 00:24:17,190 --> 00:24:17,200 length of the unthreaded portion 1255 00:24:17,200 --> 00:24:18,390 length of the unthreaded portion of the fastener 1256 00:24:18,390 --> 00:24:18,400 of the fastener 1257 00:24:18,400 --> 00:24:20,470 of the fastener and when you're you have it in shear and 1258 00:24:20,470 --> 00:24:20,480 and when you're you have it in shear and 1259 00:24:20,480 --> 00:24:22,070 and when you're you have it in shear and you try to keep 1260 00:24:22,070 --> 00:24:22,080 you try to keep 1261 00:24:22,080 --> 00:24:24,870 you try to keep have no threads in the hole 1262 00:24:24,870 --> 00:24:24,880 have no threads in the hole 1263 00:24:24,880 --> 00:24:27,190 have no threads in the hole so this is this is the thing that you 1264 00:24:27,190 --> 00:24:27,200 so this is this is the thing that you 1265 00:24:27,200 --> 00:24:28,950 so this is this is the thing that you you do here 1266 00:24:28,950 --> 00:24:28,960 you do here 1267 00:24:28,960 --> 00:24:30,470 you do here uh and 1268 00:24:30,470 --> 00:24:30,480 uh and 1269 00:24:30,480 --> 00:24:33,269 uh and you're supposed to size them the 1270 00:24:33,269 --> 00:24:33,279 you're supposed to size them the 1271 00:24:33,279 --> 00:24:36,070 you're supposed to size them the fastener such that this doesn't happen 1272 00:24:36,070 --> 00:24:36,080 fastener such that this doesn't happen 1273 00:24:36,080 --> 00:24:38,390 fastener such that this doesn't happen so you put a washer under the nut 1274 00:24:38,390 --> 00:24:38,400 so you put a washer under the nut 1275 00:24:38,400 --> 00:24:40,230 so you put a washer under the nut to allow tightening without running out 1276 00:24:40,230 --> 00:24:40,240 to allow tightening without running out 1277 00:24:40,240 --> 00:24:42,149 to allow tightening without running out of threads 1278 00:24:42,149 --> 00:24:42,159 of threads 1279 00:24:42,159 --> 00:24:47,669 of threads now the aerospace fasteners the ms nas 1280 00:24:47,669 --> 00:24:47,679 now the aerospace fasteners the ms nas 1281 00:24:47,679 --> 00:24:49,350 now the aerospace fasteners the ms nas am that type 1282 00:24:49,350 --> 00:24:49,360 am that type 1283 00:24:49,360 --> 00:24:52,390 am that type are available with sheer nuts or heads 1284 00:24:52,390 --> 00:24:52,400 are available with sheer nuts or heads 1285 00:24:52,400 --> 00:24:54,870 are available with sheer nuts or heads or tension 1286 00:24:54,870 --> 00:24:54,880 or tension 1287 00:24:54,880 --> 00:24:57,990 or tension heads and nuts to save weight on design 1288 00:24:57,990 --> 00:24:58,000 heads and nuts to save weight on design 1289 00:24:58,000 --> 00:25:00,230 heads and nuts to save weight on design because if you're designing in shear you 1290 00:25:00,230 --> 00:25:00,240 because if you're designing in shear you 1291 00:25:00,240 --> 00:25:02,549 because if you're designing in shear you don't need to have that much tension so 1292 00:25:02,549 --> 00:25:02,559 don't need to have that much tension so 1293 00:25:02,559 --> 00:25:04,549 don't need to have that much tension so therefore you can go with a thinner head 1294 00:25:04,549 --> 00:25:04,559 therefore you can go with a thinner head 1295 00:25:04,559 --> 00:25:05,990 therefore you can go with a thinner head or thinner nut 1296 00:25:05,990 --> 00:25:06,000 or thinner nut 1297 00:25:06,000 --> 00:25:08,950 or thinner nut so we have illustrations of those in the 1298 00:25:08,950 --> 00:25:08,960 so we have illustrations of those in the 1299 00:25:08,960 --> 00:25:13,750 so we have illustrations of those in the next figure 1300 00:25:13,750 --> 00:25:13,760 1301 00:25:13,760 --> 00:25:15,990 here is the grip length 1302 00:25:15,990 --> 00:25:16,000 here is the grip length 1303 00:25:16,000 --> 00:25:18,390 here is the grip length illustration it's the bottom of the head 1304 00:25:18,390 --> 00:25:18,400 illustration it's the bottom of the head 1305 00:25:18,400 --> 00:25:21,190 illustration it's the bottom of the head to the end of the threads 1306 00:25:21,190 --> 00:25:21,200 to the end of the threads 1307 00:25:21,200 --> 00:25:22,549 to the end of the threads and 1308 00:25:22,549 --> 00:25:22,559 and 1309 00:25:22,559 --> 00:25:25,669 and here is a shear head for a same size 1310 00:25:25,669 --> 00:25:25,679 here is a shear head for a same size 1311 00:25:25,679 --> 00:25:27,269 here is a shear head for a same size fastener it's an eighth of an inch thick 1312 00:25:27,269 --> 00:25:27,279 fastener it's an eighth of an inch thick 1313 00:25:27,279 --> 00:25:29,190 fastener it's an eighth of an inch thick down here it's uh 1314 00:25:29,190 --> 00:25:29,200 down here it's uh 1315 00:25:29,200 --> 00:25:31,830 down here it's uh 5 30 seconds 1316 00:25:31,830 --> 00:25:31,840 5 30 seconds 1317 00:25:31,840 --> 00:25:35,830 5 30 seconds for a tension type 1318 00:25:35,830 --> 00:25:35,840 1319 00:25:35,840 --> 00:25:38,070 and notice two specs here that are 1320 00:25:38,070 --> 00:25:38,080 and notice two specs here that are 1321 00:25:38,080 --> 00:25:39,990 and notice two specs here that are called out 1322 00:25:39,990 --> 00:25:40,000 called out 1323 00:25:40,000 --> 00:25:41,590 called out which 1324 00:25:41,590 --> 00:25:41,600 which 1325 00:25:41,600 --> 00:25:43,510 which those of you that are familiar with the 1326 00:25:43,510 --> 00:25:43,520 those of you that are familiar with the 1327 00:25:43,520 --> 00:25:45,590 those of you that are familiar with the fasteners this is for j threads here the 1328 00:25:45,590 --> 00:25:45,600 fasteners this is for j threads here the 1329 00:25:45,600 --> 00:25:49,110 fasteners this is for j threads here the mill s 8879 and this is for the two 1330 00:25:49,110 --> 00:25:49,120 mill s 8879 and this is for the two 1331 00:25:49,120 --> 00:25:51,029 mill s 8879 and this is for the two two or class two or three and the 1332 00:25:51,029 --> 00:25:51,039 two or class two or three and the 1333 00:25:51,039 --> 00:25:56,630 two or class two or three and the standard threads 1334 00:25:56,630 --> 00:25:56,640 1335 00:25:56,640 --> 00:25:58,549 here is a 1336 00:25:58,549 --> 00:25:58,559 here is a 1337 00:25:58,559 --> 00:26:01,190 here is a shear nut and a tension nut well you see 1338 00:26:01,190 --> 00:26:01,200 shear nut and a tension nut well you see 1339 00:26:01,200 --> 00:26:04,149 shear nut and a tension nut well you see the shear nut is pretty thin 203 versus 1340 00:26:04,149 --> 00:26:04,159 the shear nut is pretty thin 203 versus 1341 00:26:04,159 --> 00:26:07,430 the shear nut is pretty thin 203 versus 284 for the tension nut so if you have a 1342 00:26:07,430 --> 00:26:07,440 284 for the tension nut so if you have a 1343 00:26:07,440 --> 00:26:10,310 284 for the tension nut so if you have a joint that is primarily shear you can 1344 00:26:10,310 --> 00:26:10,320 joint that is primarily shear you can 1345 00:26:10,320 --> 00:26:12,470 joint that is primarily shear you can put in a little nut like that and if 1346 00:26:12,470 --> 00:26:12,480 put in a little nut like that and if 1347 00:26:12,480 --> 00:26:14,789 put in a little nut like that and if you're using several hundred of them 1348 00:26:14,789 --> 00:26:14,799 you're using several hundred of them 1349 00:26:14,799 --> 00:26:16,870 you're using several hundred of them it saves you quite a bit in weight 1350 00:26:16,870 --> 00:26:16,880 it saves you quite a bit in weight 1351 00:26:16,880 --> 00:26:24,710 it saves you quite a bit in weight on a airframe 1352 00:26:24,710 --> 00:26:24,720 1353 00:26:24,720 --> 00:26:26,549 now here's here's another thing i keep 1354 00:26:26,549 --> 00:26:26,559 now here's here's another thing i keep 1355 00:26:26,559 --> 00:26:30,390 now here's here's another thing i keep coming back to avoid tapped holes 1356 00:26:30,390 --> 00:26:30,400 coming back to avoid tapped holes 1357 00:26:30,400 --> 00:26:32,310 coming back to avoid tapped holes uh we covered the tap tools and the type 1358 00:26:32,310 --> 00:26:32,320 uh we covered the tap tools and the type 1359 00:26:32,320 --> 00:26:33,510 uh we covered the tap tools and the type of taps 1360 00:26:33,510 --> 00:26:33,520 of taps 1361 00:26:33,520 --> 00:26:35,909 of taps and some here's some more reasons for 1362 00:26:35,909 --> 00:26:35,919 and some here's some more reasons for 1363 00:26:35,919 --> 00:26:39,590 and some here's some more reasons for avoiding tapped holes cost 1364 00:26:39,590 --> 00:26:39,600 avoiding tapped holes cost 1365 00:26:39,600 --> 00:26:41,350 avoiding tapped holes cost drilling and tapping a hole is expensive 1366 00:26:41,350 --> 00:26:41,360 drilling and tapping a hole is expensive 1367 00:26:41,360 --> 00:26:42,789 drilling and tapping a hole is expensive compared to drilling a clearance hole 1368 00:26:42,789 --> 00:26:42,799 compared to drilling a clearance hole 1369 00:26:42,799 --> 00:26:45,190 compared to drilling a clearance hole for a nut and bolt assembly 1370 00:26:45,190 --> 00:26:45,200 for a nut and bolt assembly 1371 00:26:45,200 --> 00:26:46,789 for a nut and bolt assembly inspection 1372 00:26:46,789 --> 00:26:46,799 inspection 1373 00:26:46,799 --> 00:26:48,710 inspection about the only thing you do 1374 00:26:48,710 --> 00:26:48,720 about the only thing you do 1375 00:26:48,720 --> 00:26:53,269 about the only thing you do with a tapped hole is a go no-go gauge 1376 00:26:53,269 --> 00:26:53,279 with a tapped hole is a go no-go gauge 1377 00:26:53,279 --> 00:26:55,909 with a tapped hole is a go no-go gauge and a minimum thread diameter check just 1378 00:26:55,909 --> 00:26:55,919 and a minimum thread diameter check just 1379 00:26:55,919 --> 00:26:58,789 and a minimum thread diameter check just by running a pin through it 1380 00:26:58,789 --> 00:26:58,799 by running a pin through it 1381 00:26:58,799 --> 00:27:01,190 by running a pin through it and the root radius you can't measure 1382 00:27:01,190 --> 00:27:01,200 and the root radius you can't measure 1383 00:27:01,200 --> 00:27:02,630 and the root radius you can't measure very well 1384 00:27:02,630 --> 00:27:02,640 very well 1385 00:27:02,640 --> 00:27:04,789 very well and since there's no such thing as a unj 1386 00:27:04,789 --> 00:27:04,799 and since there's no such thing as a unj 1387 00:27:04,799 --> 00:27:07,110 and since there's no such thing as a unj tap the root radius is not rounded if 1388 00:27:07,110 --> 00:27:07,120 tap the root radius is not rounded if 1389 00:27:07,120 --> 00:27:09,190 tap the root radius is not rounded if the hole's blind it'll have burrs 1390 00:27:09,190 --> 00:27:09,200 the hole's blind it'll have burrs 1391 00:27:09,200 --> 00:27:11,029 the hole's blind it'll have burrs shavings and everything else and you're 1392 00:27:11,029 --> 00:27:11,039 shavings and everything else and you're 1393 00:27:11,039 --> 00:27:18,070 shavings and everything else and you're just stuck with it 1394 00:27:18,070 --> 00:27:18,080 1395 00:27:18,080 --> 00:27:19,269 now here's the 1396 00:27:19,269 --> 00:27:19,279 now here's the 1397 00:27:19,279 --> 00:27:21,110 now here's the the the other 1398 00:27:21,110 --> 00:27:21,120 the the other 1399 00:27:21,120 --> 00:27:25,110 the the other type of design that you need to look at 1400 00:27:25,110 --> 00:27:25,120 type of design that you need to look at 1401 00:27:25,120 --> 00:27:26,149 type of design that you need to look at is 1402 00:27:26,149 --> 00:27:26,159 is 1403 00:27:26,159 --> 00:27:29,190 is tension loads on a fastener group 1404 00:27:29,190 --> 00:27:29,200 tension loads on a fastener group 1405 00:27:29,200 --> 00:27:30,470 tension loads on a fastener group and uh 1406 00:27:30,470 --> 00:27:30,480 and uh 1407 00:27:30,480 --> 00:27:32,310 and uh at the time that i did this one i 1408 00:27:32,310 --> 00:27:32,320 at the time that i did this one i 1409 00:27:32,320 --> 00:27:34,389 at the time that i did this one i couldn't find one anywhere in anybody's 1410 00:27:34,389 --> 00:27:34,399 couldn't find one anywhere in anybody's 1411 00:27:34,399 --> 00:27:36,870 couldn't find one anywhere in anybody's book so i had to draw this one up myself 1412 00:27:36,870 --> 00:27:36,880 book so i had to draw this one up myself 1413 00:27:36,880 --> 00:27:38,950 book so i had to draw this one up myself but it didn't get too fatigued during 1414 00:27:38,950 --> 00:27:38,960 but it didn't get too fatigued during 1415 00:27:38,960 --> 00:27:41,350 but it didn't get too fatigued during our scanning so i guess it's all right 1416 00:27:41,350 --> 00:27:41,360 our scanning so i guess it's all right 1417 00:27:41,360 --> 00:27:43,269 our scanning so i guess it's all right and 1418 00:27:43,269 --> 00:27:43,279 and 1419 00:27:43,279 --> 00:27:45,029 and the 1420 00:27:45,029 --> 00:27:45,039 the 1421 00:27:45,039 --> 00:27:47,750 the here we have eight fasteners on a 1422 00:27:47,750 --> 00:27:47,760 here we have eight fasteners on a 1423 00:27:47,760 --> 00:27:49,909 here we have eight fasteners on a bracket that has two different loads on 1424 00:27:49,909 --> 00:27:49,919 bracket that has two different loads on 1425 00:27:49,919 --> 00:27:52,710 bracket that has two different loads on it it has a direct tension load p1 and 1426 00:27:52,710 --> 00:27:52,720 it it has a direct tension load p1 and 1427 00:27:52,720 --> 00:27:54,789 it it has a direct tension load p1 and it has a shear load p2 which also gives 1428 00:27:54,789 --> 00:27:54,799 it has a shear load p2 which also gives 1429 00:27:54,799 --> 00:27:56,870 it has a shear load p2 which also gives you a bending moment 1430 00:27:56,870 --> 00:27:56,880 you a bending moment 1431 00:27:56,880 --> 00:27:57,990 you a bending moment so 1432 00:27:57,990 --> 00:27:58,000 so 1433 00:27:58,000 --> 00:28:00,710 so what you're trying to do is get the 1434 00:28:00,710 --> 00:28:00,720 what you're trying to do is get the 1435 00:28:00,720 --> 00:28:02,470 what you're trying to do is get the total load 1436 00:28:02,470 --> 00:28:02,480 total load 1437 00:28:02,480 --> 00:28:04,630 total load on all of these fasteners 1438 00:28:04,630 --> 00:28:04,640 on all of these fasteners 1439 00:28:04,640 --> 00:28:06,470 on all of these fasteners using the different loads that we have 1440 00:28:06,470 --> 00:28:06,480 using the different loads that we have 1441 00:28:06,480 --> 00:28:07,750 using the different loads that we have there 1442 00:28:07,750 --> 00:28:07,760 there 1443 00:28:07,760 --> 00:28:08,950 there all right 1444 00:28:08,950 --> 00:28:08,960 all right 1445 00:28:08,960 --> 00:28:10,630 all right the 1446 00:28:10,630 --> 00:28:10,640 the 1447 00:28:10,640 --> 00:28:13,190 the moment from the load 1448 00:28:13,190 --> 00:28:13,200 moment from the load 1449 00:28:13,200 --> 00:28:15,510 moment from the load if you now here here's another thing 1450 00:28:15,510 --> 00:28:15,520 if you now here here's another thing 1451 00:28:15,520 --> 00:28:16,950 if you now here here's another thing that's different from the other one is 1452 00:28:16,950 --> 00:28:16,960 that's different from the other one is 1453 00:28:16,960 --> 00:28:19,510 that's different from the other one is where do you measure r from 1454 00:28:19,510 --> 00:28:19,520 where do you measure r from 1455 00:28:19,520 --> 00:28:22,470 where do you measure r from r is measured from the healing point 1456 00:28:22,470 --> 00:28:22,480 r is measured from the healing point 1457 00:28:22,480 --> 00:28:24,950 r is measured from the healing point for your sigma r squared 1458 00:28:24,950 --> 00:28:24,960 for your sigma r squared 1459 00:28:24,960 --> 00:28:27,110 for your sigma r squared because if this thing goes into 1460 00:28:27,110 --> 00:28:27,120 because if this thing goes into 1461 00:28:27,120 --> 00:28:30,070 because if this thing goes into compression over here 1462 00:28:30,070 --> 00:28:30,080 compression over here 1463 00:28:30,080 --> 00:28:31,830 compression over here then you're not getting anything out of 1464 00:28:31,830 --> 00:28:31,840 then you're not getting anything out of 1465 00:28:31,840 --> 00:28:33,510 then you're not getting anything out of it for your tension load so you can't 1466 00:28:33,510 --> 00:28:33,520 it for your tension load so you can't 1467 00:28:33,520 --> 00:28:36,389 it for your tension load so you can't use those two fasteners to carry the 1468 00:28:36,389 --> 00:28:36,399 use those two fasteners to carry the 1469 00:28:36,399 --> 00:28:37,669 use those two fasteners to carry the tension because they're in compression 1470 00:28:37,669 --> 00:28:37,679 tension because they're in compression 1471 00:28:37,679 --> 00:28:38,950 tension because they're in compression they're going to not going to help you 1472 00:28:38,950 --> 00:28:38,960 they're going to not going to help you 1473 00:28:38,960 --> 00:28:40,310 they're going to not going to help you any 1474 00:28:40,310 --> 00:28:40,320 any 1475 00:28:40,320 --> 00:28:41,110 any so 1476 00:28:41,110 --> 00:28:41,120 so 1477 00:28:41,120 --> 00:28:43,190 so what i did in this case 1478 00:28:43,190 --> 00:28:43,200 what i did in this case 1479 00:28:43,200 --> 00:28:44,870 what i did in this case since it's a bracket and this is a 1480 00:28:44,870 --> 00:28:44,880 since it's a bracket and this is a 1481 00:28:44,880 --> 00:28:46,870 since it's a bracket and this is a flange sticking out i said okay this 1482 00:28:46,870 --> 00:28:46,880 flange sticking out i said okay this 1483 00:28:46,880 --> 00:28:48,950 flange sticking out i said okay this thing is hard up to here so i'll measure 1484 00:28:48,950 --> 00:28:48,960 thing is hard up to here so i'll measure 1485 00:28:48,960 --> 00:28:51,350 thing is hard up to here so i'll measure my r's from that 1486 00:28:51,350 --> 00:28:51,360 my r's from that 1487 00:28:51,360 --> 00:28:52,389 my r's from that uh 1488 00:28:52,389 --> 00:28:52,399 uh 1489 00:28:52,399 --> 00:28:54,149 uh point to the right 1490 00:28:54,149 --> 00:28:54,159 point to the right 1491 00:28:54,159 --> 00:28:56,630 point to the right so i only have for my 1492 00:28:56,630 --> 00:28:56,640 so i only have for my 1493 00:28:56,640 --> 00:28:58,470 so i only have for my sigma r squared 1494 00:28:58,470 --> 00:28:58,480 sigma r squared 1495 00:28:58,480 --> 00:29:01,029 sigma r squared i only have six fasteners in it 1496 00:29:01,029 --> 00:29:01,039 i only have six fasteners in it 1497 00:29:01,039 --> 00:29:03,590 i only have six fasteners in it but then for the total shear 1498 00:29:03,590 --> 00:29:03,600 but then for the total shear 1499 00:29:03,600 --> 00:29:05,909 but then for the total shear i'm using all eight of them and for the 1500 00:29:05,909 --> 00:29:05,919 i'm using all eight of them and for the 1501 00:29:05,919 --> 00:29:08,230 i'm using all eight of them and for the total tension i'm using all eight of 1502 00:29:08,230 --> 00:29:08,240 total tension i'm using all eight of 1503 00:29:08,240 --> 00:29:09,830 total tension i'm using all eight of them 1504 00:29:09,830 --> 00:29:09,840 them 1505 00:29:09,840 --> 00:29:13,269 them so in doing that you can 1506 00:29:13,269 --> 00:29:13,279 so in doing that you can 1507 00:29:13,279 --> 00:29:16,230 so in doing that you can calculate the sigma r squared you divide 1508 00:29:16,230 --> 00:29:16,240 calculate the sigma r squared you divide 1509 00:29:16,240 --> 00:29:17,990 calculate the sigma r squared you divide the uh 1510 00:29:17,990 --> 00:29:18,000 the uh 1511 00:29:18,000 --> 00:29:20,070 the uh the load i better leave this up here 1512 00:29:20,070 --> 00:29:20,080 the load i better leave this up here 1513 00:29:20,080 --> 00:29:21,669 the load i better leave this up here from from my standpoint here for a 1514 00:29:21,669 --> 00:29:21,679 from from my standpoint here for a 1515 00:29:21,679 --> 00:29:22,549 from from my standpoint here for a moment 1516 00:29:22,549 --> 00:29:22,559 moment 1517 00:29:22,559 --> 00:29:24,549 moment you can divide the load by eight to get 1518 00:29:24,549 --> 00:29:24,559 you can divide the load by eight to get 1519 00:29:24,559 --> 00:29:27,430 you can divide the load by eight to get the one the shear loads then you can 1520 00:29:27,430 --> 00:29:27,440 the one the shear loads then you can 1521 00:29:27,440 --> 00:29:28,710 the one the shear loads then you can calculate 1522 00:29:28,710 --> 00:29:28,720 calculate 1523 00:29:28,720 --> 00:29:29,990 calculate the 1524 00:29:29,990 --> 00:29:30,000 the 1525 00:29:30,000 --> 00:29:33,830 the uh moment which is the p2 times h 1526 00:29:33,830 --> 00:29:33,840 uh moment which is the p2 times h 1527 00:29:33,840 --> 00:29:35,750 uh moment which is the p2 times h then take the r7 which was the one 1528 00:29:35,750 --> 00:29:35,760 then take the r7 which was the one 1529 00:29:35,760 --> 00:29:38,470 then take the r7 which was the one further stout and use the sigma r sub n 1530 00:29:38,470 --> 00:29:38,480 further stout and use the sigma r sub n 1531 00:29:38,480 --> 00:29:40,549 further stout and use the sigma r sub n squared and you can get a load then 1532 00:29:40,549 --> 00:29:40,559 squared and you can get a load then 1533 00:29:40,559 --> 00:29:42,549 squared and you can get a load then attention load from the moment 1534 00:29:42,549 --> 00:29:42,559 attention load from the moment 1535 00:29:42,559 --> 00:29:45,029 attention load from the moment you have a piece of t on there which you 1536 00:29:45,029 --> 00:29:45,039 you have a piece of t on there which you 1537 00:29:45,039 --> 00:29:46,630 you have a piece of t on there which you divide by eight to give you the 1538 00:29:46,630 --> 00:29:46,640 divide by eight to give you the 1539 00:29:46,640 --> 00:29:48,389 divide by eight to give you the additional tension load 1540 00:29:48,389 --> 00:29:48,399 additional tension load 1541 00:29:48,399 --> 00:29:50,630 additional tension load and you can go in then and 1542 00:29:50,630 --> 00:29:50,640 and you can go in then and 1543 00:29:50,640 --> 00:29:51,909 and you can go in then and calculate 1544 00:29:51,909 --> 00:29:51,919 calculate 1545 00:29:51,919 --> 00:29:55,269 calculate the total load in tension then you have 1546 00:29:55,269 --> 00:29:55,279 the total load in tension then you have 1547 00:29:55,279 --> 00:29:57,430 the total load in tension then you have the shear load which was the p2 over 1548 00:29:57,430 --> 00:29:57,440 the shear load which was the p2 over 1549 00:29:57,440 --> 00:29:58,310 the shear load which was the p2 over eight 1550 00:29:58,310 --> 00:29:58,320 eight 1551 00:29:58,320 --> 00:30:01,510 eight and you can take those two loads now 1552 00:30:01,510 --> 00:30:01,520 and you can take those two loads now 1553 00:30:01,520 --> 00:30:05,029 and you can take those two loads now and go in and use stress ratios 1554 00:30:05,029 --> 00:30:05,039 and go in and use stress ratios 1555 00:30:05,039 --> 00:30:07,269 and go in and use stress ratios and calculate the margin of safety on 1556 00:30:07,269 --> 00:30:07,279 and calculate the margin of safety on 1557 00:30:07,279 --> 00:30:10,310 and calculate the margin of safety on the fastener for the total loading 1558 00:30:10,310 --> 00:30:10,320 the fastener for the total loading 1559 00:30:10,320 --> 00:30:12,789 the fastener for the total loading see here was the a better better print 1560 00:30:12,789 --> 00:30:12,799 see here was the a better better print 1561 00:30:12,799 --> 00:30:15,750 see here was the a better better print showing the the one for 1562 00:30:15,750 --> 00:30:15,760 showing the the one for 1563 00:30:15,760 --> 00:30:18,789 showing the the one for the uh p sub m value where you're 1564 00:30:18,789 --> 00:30:18,799 the uh p sub m value where you're 1565 00:30:18,799 --> 00:30:20,310 the uh p sub m value where you're actually getting the moment was the p2 1566 00:30:20,310 --> 00:30:20,320 actually getting the moment was the p2 1567 00:30:20,320 --> 00:30:23,029 actually getting the moment was the p2 times h and that times r7 over the sigma 1568 00:30:23,029 --> 00:30:23,039 times h and that times r7 over the sigma 1569 00:30:23,039 --> 00:30:27,590 times h and that times r7 over the sigma r sub n squared 1570 00:30:27,590 --> 00:30:27,600 1571 00:30:27,600 --> 00:30:30,149 now the tensile load that your preload 1572 00:30:30,149 --> 00:30:30,159 now the tensile load that your preload 1573 00:30:30,159 --> 00:30:32,230 now the tensile load that your preload that you're putting on these fasteners 1574 00:30:32,230 --> 00:30:32,240 that you're putting on these fasteners 1575 00:30:32,240 --> 00:30:34,549 that you're putting on these fasteners has to exceed p or you're in trouble 1576 00:30:34,549 --> 00:30:34,559 has to exceed p or you're in trouble 1577 00:30:34,559 --> 00:30:37,110 has to exceed p or you're in trouble because you don't want any joint 1578 00:30:37,110 --> 00:30:37,120 because you don't want any joint 1579 00:30:37,120 --> 00:30:39,590 because you don't want any joint loosening 1580 00:30:39,590 --> 00:30:39,600 loosening 1581 00:30:39,600 --> 00:30:42,389 loosening combined shear and tension loading 1582 00:30:42,389 --> 00:30:42,399 combined shear and tension loading 1583 00:30:42,399 --> 00:30:44,230 combined shear and tension loading now on this 1584 00:30:44,230 --> 00:30:44,240 now on this 1585 00:30:44,240 --> 00:30:45,510 now on this you have 1586 00:30:45,510 --> 00:30:45,520 you have 1587 00:30:45,520 --> 00:30:47,830 you have you get all your summation of loads in 1588 00:30:47,830 --> 00:30:47,840 you get all your summation of loads in 1589 00:30:47,840 --> 00:30:49,430 you get all your summation of loads in the shear direction you get all your 1590 00:30:49,430 --> 00:30:49,440 the shear direction you get all your 1591 00:30:49,440 --> 00:30:51,510 the shear direction you get all your summation of loads in the tension 1592 00:30:51,510 --> 00:30:51,520 summation of loads in the tension 1593 00:30:51,520 --> 00:30:53,029 summation of loads in the tension direction 1594 00:30:53,029 --> 00:30:53,039 direction 1595 00:30:53,039 --> 00:30:54,870 direction and then 1596 00:30:54,870 --> 00:30:54,880 and then 1597 00:30:54,880 --> 00:30:57,509 and then you could use a mortar circle 1598 00:30:57,509 --> 00:30:57,519 you could use a mortar circle 1599 00:30:57,519 --> 00:31:00,230 you could use a mortar circle and work with it and get the 1600 00:31:00,230 --> 00:31:00,240 and work with it and get the 1601 00:31:00,240 --> 00:31:02,149 and work with it and get the principal stresses and that type of 1602 00:31:02,149 --> 00:31:02,159 principal stresses and that type of 1603 00:31:02,159 --> 00:31:03,509 principal stresses and that type of thing and 1604 00:31:03,509 --> 00:31:03,519 thing and 1605 00:31:03,519 --> 00:31:05,350 thing and calculate out 1606 00:31:05,350 --> 00:31:05,360 calculate out 1607 00:31:05,360 --> 00:31:07,909 calculate out a and allowable and a margin of safety 1608 00:31:07,909 --> 00:31:07,919 a and allowable and a margin of safety 1609 00:31:07,919 --> 00:31:09,590 a and allowable and a margin of safety that way but it's easier to use these 1610 00:31:09,590 --> 00:31:09,600 that way but it's easier to use these 1611 00:31:09,600 --> 00:31:11,590 that way but it's easier to use these stress ratios because that's doing the 1612 00:31:11,590 --> 00:31:11,600 stress ratios because that's doing the 1613 00:31:11,600 --> 00:31:12,789 stress ratios because that's doing the same thing 1614 00:31:12,789 --> 00:31:12,799 same thing 1615 00:31:12,799 --> 00:31:15,110 same thing so what you do is you get two factors 1616 00:31:15,110 --> 00:31:15,120 so what you do is you get two factors 1617 00:31:15,120 --> 00:31:17,509 so what you do is you get two factors you get a 1618 00:31:17,509 --> 00:31:17,519 you get a 1619 00:31:17,519 --> 00:31:20,230 you get a r sub s or r sub t here which is the 1620 00:31:20,230 --> 00:31:20,240 r sub s or r sub t here which is the 1621 00:31:20,240 --> 00:31:22,470 r sub s or r sub t here which is the actual shear load over the allowable 1622 00:31:22,470 --> 00:31:22,480 actual shear load over the allowable 1623 00:31:22,480 --> 00:31:24,310 actual shear load over the allowable shear load for that fastener now in this 1624 00:31:24,310 --> 00:31:24,320 shear load for that fastener now in this 1625 00:31:24,320 --> 00:31:25,190 shear load for that fastener now in this case 1626 00:31:25,190 --> 00:31:25,200 case 1627 00:31:25,200 --> 00:31:27,430 case you can work in pounds you can work in 1628 00:31:27,430 --> 00:31:27,440 you can work in pounds you can work in 1629 00:31:27,440 --> 00:31:29,590 you can work in pounds you can work in uh stress either when you want to as 1630 00:31:29,590 --> 00:31:29,600 uh stress either when you want to as 1631 00:31:29,600 --> 00:31:32,389 uh stress either when you want to as long as you're consistent in your units 1632 00:31:32,389 --> 00:31:32,399 long as you're consistent in your units 1633 00:31:32,399 --> 00:31:34,310 long as you're consistent in your units so you get a 1634 00:31:34,310 --> 00:31:34,320 so you get a 1635 00:31:34,320 --> 00:31:37,029 so you get a a factor there you get one from tension 1636 00:31:37,029 --> 00:31:37,039 a factor there you get one from tension 1637 00:31:37,039 --> 00:31:38,549 a factor there you get one from tension the actual tension load over the 1638 00:31:38,549 --> 00:31:38,559 the actual tension load over the 1639 00:31:38,559 --> 00:31:39,830 the actual tension load over the allowable 1640 00:31:39,830 --> 00:31:39,840 allowable 1641 00:31:39,840 --> 00:31:41,269 allowable and then you get 1642 00:31:41,269 --> 00:31:41,279 and then you get 1643 00:31:41,279 --> 00:31:44,230 and then you get a margin of safety 1644 00:31:44,230 --> 00:31:44,240 a margin of safety 1645 00:31:44,240 --> 00:31:47,430 a margin of safety which takes the actual load 1646 00:31:47,430 --> 00:31:47,440 which takes the actual load 1647 00:31:47,440 --> 00:31:50,389 which takes the actual load over the one you calculated here minus 1648 00:31:50,389 --> 00:31:50,399 over the one you calculated here minus 1649 00:31:50,399 --> 00:31:51,350 over the one you calculated here minus one 1650 00:31:51,350 --> 00:31:51,360 one 1651 00:31:51,360 --> 00:31:53,669 one give a margin of safety now what happens 1652 00:31:53,669 --> 00:31:53,679 give a margin of safety now what happens 1653 00:31:53,679 --> 00:31:56,630 give a margin of safety now what happens with these these values when you combine 1654 00:31:56,630 --> 00:31:56,640 with these these values when you combine 1655 00:31:56,640 --> 00:31:58,549 with these these values when you combine them 1656 00:31:58,549 --> 00:31:58,559 them 1657 00:31:58,559 --> 00:31:59,669 them you get 1658 00:31:59,669 --> 00:31:59,679 you get 1659 00:31:59,679 --> 00:32:00,549 you get two 1660 00:32:00,549 --> 00:32:00,559 two 1661 00:32:00,559 --> 00:32:02,230 two values 1662 00:32:02,230 --> 00:32:02,240 values 1663 00:32:02,240 --> 00:32:04,310 values that have better be less than one for 1664 00:32:04,310 --> 00:32:04,320 that have better be less than one for 1665 00:32:04,320 --> 00:32:05,750 that have better be less than one for each one of them 1666 00:32:05,750 --> 00:32:05,760 each one of them 1667 00:32:05,760 --> 00:32:07,029 each one of them because you don't want either one of 1668 00:32:07,029 --> 00:32:07,039 because you don't want either one of 1669 00:32:07,039 --> 00:32:08,549 because you don't want either one of them be greater than one or you're in 1670 00:32:08,549 --> 00:32:08,559 them be greater than one or you're in 1671 00:32:08,559 --> 00:32:11,350 them be greater than one or you're in trouble on the design 1672 00:32:11,350 --> 00:32:11,360 trouble on the design 1673 00:32:11,360 --> 00:32:12,470 trouble on the design so 1674 00:32:12,470 --> 00:32:12,480 so 1675 00:32:12,480 --> 00:32:15,190 so you have these and they have exponents x 1676 00:32:15,190 --> 00:32:15,200 you have these and they have exponents x 1677 00:32:15,200 --> 00:32:16,549 you have these and they have exponents x and y 1678 00:32:16,549 --> 00:32:16,559 and y 1679 00:32:16,559 --> 00:32:18,630 and y now it depends on your degree of 1680 00:32:18,630 --> 00:32:18,640 now it depends on your degree of 1681 00:32:18,640 --> 00:32:21,430 now it depends on your degree of conservatism as to how how big an 1682 00:32:21,430 --> 00:32:21,440 conservatism as to how how big an 1683 00:32:21,440 --> 00:32:23,509 conservatism as to how how big an exponent you use for those because of 1684 00:32:23,509 --> 00:32:23,519 exponent you use for those because of 1685 00:32:23,519 --> 00:32:25,430 exponent you use for those because of course the 1686 00:32:25,430 --> 00:32:25,440 course the 1687 00:32:25,440 --> 00:32:27,590 course the the bigger the exponent goes the more 1688 00:32:27,590 --> 00:32:27,600 the bigger the exponent goes the more 1689 00:32:27,600 --> 00:32:29,750 the bigger the exponent goes the more unconservative you become 1690 00:32:29,750 --> 00:32:29,760 unconservative you become 1691 00:32:29,760 --> 00:32:32,149 unconservative you become because the sum of those two have to be 1692 00:32:32,149 --> 00:32:32,159 because the sum of those two have to be 1693 00:32:32,159 --> 00:32:33,509 because the sum of those two have to be less than one in order to have a 1694 00:32:33,509 --> 00:32:33,519 less than one in order to have a 1695 00:32:33,519 --> 00:32:34,950 less than one in order to have a positive margin 1696 00:32:34,950 --> 00:32:34,960 positive margin 1697 00:32:34,960 --> 00:32:38,310 positive margin because margin of safety 1698 00:32:38,310 --> 00:32:38,320 because margin of safety 1699 00:32:38,320 --> 00:32:41,110 because margin of safety and safety as a safety factor of one if 1700 00:32:41,110 --> 00:32:41,120 and safety as a safety factor of one if 1701 00:32:41,120 --> 00:32:43,509 and safety as a safety factor of one if you will so a margin safety of zero is a 1702 00:32:43,509 --> 00:32:43,519 you will so a margin safety of zero is a 1703 00:32:43,519 --> 00:32:45,509 you will so a margin safety of zero is a safety factor of one 1704 00:32:45,509 --> 00:32:45,519 safety factor of one 1705 00:32:45,519 --> 00:32:47,669 safety factor of one so therefore if uh 1706 00:32:47,669 --> 00:32:47,679 so therefore if uh 1707 00:32:47,679 --> 00:32:49,430 so therefore if uh people say oh well gee i got a margin of 1708 00:32:49,430 --> 00:32:49,440 people say oh well gee i got a margin of 1709 00:32:49,440 --> 00:32:50,950 people say oh well gee i got a margin of safety of 1710 00:32:50,950 --> 00:32:50,960 safety of 1711 00:32:50,960 --> 00:32:53,190 safety of 0.03 on that part well that's still good 1712 00:32:53,190 --> 00:32:53,200 0.03 on that part well that's still good 1713 00:32:53,200 --> 00:32:57,430 0.03 on that part well that's still good because that's 1.03 safety factor-wise 1714 00:32:57,430 --> 00:32:57,440 because that's 1.03 safety factor-wise 1715 00:32:57,440 --> 00:32:59,029 because that's 1.03 safety factor-wise and that's the way the aerospace 1716 00:32:59,029 --> 00:32:59,039 and that's the way the aerospace 1717 00:32:59,039 --> 00:33:01,430 and that's the way the aerospace industry has been doing it 1718 00:33:01,430 --> 00:33:01,440 industry has been doing it 1719 00:33:01,440 --> 00:33:03,909 industry has been doing it ever since glenn l martin 1720 00:33:03,909 --> 00:33:03,919 ever since glenn l martin 1721 00:33:03,919 --> 00:33:06,149 ever since glenn l martin so here are these curves that you can 1722 00:33:06,149 --> 00:33:06,159 so here are these curves that you can 1723 00:33:06,159 --> 00:33:07,269 so here are these curves that you can use 1724 00:33:07,269 --> 00:33:07,279 use 1725 00:33:07,279 --> 00:33:09,350 use and it depends on how conservative or 1726 00:33:09,350 --> 00:33:09,360 and it depends on how conservative or 1727 00:33:09,360 --> 00:33:11,350 and it depends on how conservative or unconservative you want to be now for if 1728 00:33:11,350 --> 00:33:11,360 unconservative you want to be now for if 1729 00:33:11,360 --> 00:33:13,110 unconservative you want to be now for if you're the belt and suspenders type and 1730 00:33:13,110 --> 00:33:13,120 you're the belt and suspenders type and 1731 00:33:13,120 --> 00:33:14,389 you're the belt and suspenders type and want to make sure everything's all right 1732 00:33:14,389 --> 00:33:14,399 want to make sure everything's all right 1733 00:33:14,399 --> 00:33:16,630 want to make sure everything's all right you use a straight line version here 1734 00:33:16,630 --> 00:33:16,640 you use a straight line version here 1735 00:33:16,640 --> 00:33:17,669 you use a straight line version here which is 1736 00:33:17,669 --> 00:33:17,679 which is 1737 00:33:17,679 --> 00:33:18,630 which is uh 1738 00:33:18,630 --> 00:33:18,640 uh 1739 00:33:18,640 --> 00:33:21,430 uh just uses no exponents at all 1740 00:33:21,430 --> 00:33:21,440 just uses no exponents at all 1741 00:33:21,440 --> 00:33:23,110 just uses no exponents at all and calculate the margin and that one is 1742 00:33:23,110 --> 00:33:23,120 and calculate the margin and that one is 1743 00:33:23,120 --> 00:33:25,509 and calculate the margin and that one is a lot safer if you want to get 1744 00:33:25,509 --> 00:33:25,519 a lot safer if you want to get 1745 00:33:25,519 --> 00:33:27,590 a lot safer if you want to get more unsafe you can go further out on 1746 00:33:27,590 --> 00:33:27,600 more unsafe you can go further out on 1747 00:33:27,600 --> 00:33:30,870 more unsafe you can go further out on these by squaring and cubing these 1748 00:33:30,870 --> 00:33:30,880 these by squaring and cubing these 1749 00:33:30,880 --> 00:33:33,590 these by squaring and cubing these ratios and that will give you 1750 00:33:33,590 --> 00:33:33,600 ratios and that will give you 1751 00:33:33,600 --> 00:33:34,549 ratios and that will give you a 1752 00:33:34,549 --> 00:33:34,559 a 1753 00:33:34,559 --> 00:33:39,430 a better margin of safety for a given load 1754 00:33:39,430 --> 00:33:39,440 1755 00:33:39,440 --> 00:33:41,269 now here's one 1756 00:33:41,269 --> 00:33:41,279 now here's one 1757 00:33:41,279 --> 00:33:43,350 now here's one that is uh another one that has always 1758 00:33:43,350 --> 00:33:43,360 that is uh another one that has always 1759 00:33:43,360 --> 00:33:47,029 that is uh another one that has always bothered me because in school 1760 00:33:47,029 --> 00:33:47,039 bothered me because in school 1761 00:33:47,039 --> 00:33:48,950 bothered me because in school i never did 1762 00:33:48,950 --> 00:33:48,960 i never did 1763 00:33:48,960 --> 00:33:50,870 i never did like the way these professors went 1764 00:33:50,870 --> 00:33:50,880 like the way these professors went 1765 00:33:50,880 --> 00:33:53,750 like the way these professors went through horizontal shear stress 1766 00:33:53,750 --> 00:33:53,760 through horizontal shear stress 1767 00:33:53,760 --> 00:33:56,230 through horizontal shear stress and said then the determination of this 1768 00:33:56,230 --> 00:33:56,240 and said then the determination of this 1769 00:33:56,240 --> 00:33:59,669 and said then the determination of this is an exercise left up to the student 1770 00:33:59,669 --> 00:33:59,679 is an exercise left up to the student 1771 00:33:59,679 --> 00:34:00,470 is an exercise left up to the student so 1772 00:34:00,470 --> 00:34:00,480 so 1773 00:34:00,480 --> 00:34:03,269 so so anyway i went through and developed 1774 00:34:03,269 --> 00:34:03,279 so anyway i went through and developed 1775 00:34:03,279 --> 00:34:04,789 so anyway i went through and developed this 1776 00:34:04,789 --> 00:34:04,799 this 1777 00:34:04,799 --> 00:34:07,830 this for uh the uh lecture that i give on 1778 00:34:07,830 --> 00:34:07,840 for uh the uh lecture that i give on 1779 00:34:07,840 --> 00:34:09,270 for uh the uh lecture that i give on fasteners 1780 00:34:09,270 --> 00:34:09,280 fasteners 1781 00:34:09,280 --> 00:34:10,790 fasteners and shear 1782 00:34:10,790 --> 00:34:10,800 and shear 1783 00:34:10,800 --> 00:34:12,550 and shear because it always bothered me that 1784 00:34:12,550 --> 00:34:12,560 because it always bothered me that 1785 00:34:12,560 --> 00:34:14,710 because it always bothered me that nobody had explained it very well and of 1786 00:34:14,710 --> 00:34:14,720 nobody had explained it very well and of 1787 00:34:14,720 --> 00:34:15,750 nobody had explained it very well and of course when you're looking for 1788 00:34:15,750 --> 00:34:15,760 course when you're looking for 1789 00:34:15,760 --> 00:34:17,669 course when you're looking for explanations and strength materials you 1790 00:34:17,669 --> 00:34:17,679 explanations and strength materials you 1791 00:34:17,679 --> 00:34:19,510 explanations and strength materials you go back to the basics 1792 00:34:19,510 --> 00:34:19,520 go back to the basics 1793 00:34:19,520 --> 00:34:22,149 go back to the basics back to the real source timoshenko 1794 00:34:22,149 --> 00:34:22,159 back to the real source timoshenko 1795 00:34:22,159 --> 00:34:24,470 back to the real source timoshenko so i found this in an old temeschenko 1796 00:34:24,470 --> 00:34:24,480 so i found this in an old temeschenko 1797 00:34:24,480 --> 00:34:25,349 so i found this in an old temeschenko book 1798 00:34:25,349 --> 00:34:25,359 book 1799 00:34:25,359 --> 00:34:27,510 book uh in which he explained it 1800 00:34:27,510 --> 00:34:27,520 uh in which he explained it 1801 00:34:27,520 --> 00:34:29,589 uh in which he explained it and it was the book was old enough that 1802 00:34:29,589 --> 00:34:29,599 and it was the book was old enough that 1803 00:34:29,599 --> 00:34:31,270 and it was the book was old enough that he wasn't working with bolts he was 1804 00:34:31,270 --> 00:34:31,280 he wasn't working with bolts he was 1805 00:34:31,280 --> 00:34:32,829 he wasn't working with bolts he was working with nails and 1806 00:34:32,829 --> 00:34:32,839 working with nails and 1807 00:34:32,839 --> 00:34:34,869 working with nails and tubaphores but nevertheless the 1808 00:34:34,869 --> 00:34:34,879 tubaphores but nevertheless the 1809 00:34:34,879 --> 00:34:36,629 tubaphores but nevertheless the principle was the same 1810 00:34:36,629 --> 00:34:36,639 principle was the same 1811 00:34:36,639 --> 00:34:38,710 principle was the same because when you have two pieces that 1812 00:34:38,710 --> 00:34:38,720 because when you have two pieces that 1813 00:34:38,720 --> 00:34:40,629 because when you have two pieces that you want to fasten together so that they 1814 00:34:40,629 --> 00:34:40,639 you want to fasten together so that they 1815 00:34:40,639 --> 00:34:42,550 you want to fasten together so that they act as a beam 1816 00:34:42,550 --> 00:34:42,560 act as a beam 1817 00:34:42,560 --> 00:34:44,710 act as a beam you have to have enough fasteners to 1818 00:34:44,710 --> 00:34:44,720 you have to have enough fasteners to 1819 00:34:44,720 --> 00:34:49,109 you have to have enough fasteners to carry the horizontal shear stress 1820 00:34:49,109 --> 00:34:49,119 1821 00:34:49,119 --> 00:34:51,270 for that to happen so this is a method 1822 00:34:51,270 --> 00:34:51,280 for that to happen so this is a method 1823 00:34:51,280 --> 00:34:53,030 for that to happen so this is a method of calculating it 1824 00:34:53,030 --> 00:34:53,040 of calculating it 1825 00:34:53,040 --> 00:34:56,310 of calculating it and this is the the vq over ib 1826 00:34:56,310 --> 00:34:56,320 and this is the the vq over ib 1827 00:34:56,320 --> 00:34:58,150 and this is the the vq over ib shear stress 1828 00:34:58,150 --> 00:34:58,160 shear stress 1829 00:34:58,160 --> 00:34:59,430 shear stress and 1830 00:34:59,430 --> 00:34:59,440 and 1831 00:34:59,440 --> 00:35:00,550 and so i 1832 00:35:00,550 --> 00:35:00,560 so i 1833 00:35:00,560 --> 00:35:02,870 so i set up a little problem 1834 00:35:02,870 --> 00:35:02,880 set up a little problem 1835 00:35:02,880 --> 00:35:04,390 set up a little problem and work through it here and these are 1836 00:35:04,390 --> 00:35:04,400 and work through it here and these are 1837 00:35:04,400 --> 00:35:06,230 and work through it here and these are the dimensions which i think most of 1838 00:35:06,230 --> 00:35:06,240 the dimensions which i think most of 1839 00:35:06,240 --> 00:35:07,910 the dimensions which i think most of them are given on the 1840 00:35:07,910 --> 00:35:07,920 them are given on the 1841 00:35:07,920 --> 00:35:11,670 them are given on the with the figure i believe 1842 00:35:11,670 --> 00:35:11,680 1843 00:35:11,680 --> 00:35:14,630 yeah 1844 00:35:14,630 --> 00:35:14,640 1845 00:35:14,640 --> 00:35:16,710 now 1846 00:35:16,710 --> 00:35:16,720 now 1847 00:35:16,720 --> 00:35:18,790 now this is a uh 1848 00:35:18,790 --> 00:35:18,800 this is a uh 1849 00:35:18,800 --> 00:35:21,349 this is a uh the type of beam and i i just came came 1850 00:35:21,349 --> 00:35:21,359 the type of beam and i i just came came 1851 00:35:21,359 --> 00:35:23,190 the type of beam and i i just came came up with a kind of an artificial type 1852 00:35:23,190 --> 00:35:23,200 up with a kind of an artificial type 1853 00:35:23,200 --> 00:35:25,910 up with a kind of an artificial type thing to illustrate the point you have a 1854 00:35:25,910 --> 00:35:25,920 thing to illustrate the point you have a 1855 00:35:25,920 --> 00:35:29,109 thing to illustrate the point you have a 400 pounds per inch loading 1856 00:35:29,109 --> 00:35:29,119 400 pounds per inch loading 1857 00:35:29,119 --> 00:35:31,430 400 pounds per inch loading and it's 50 inches long 1858 00:35:31,430 --> 00:35:31,440 and it's 50 inches long 1859 00:35:31,440 --> 00:35:34,310 and it's 50 inches long and it's made up of two one-inch plates 1860 00:35:34,310 --> 00:35:34,320 and it's made up of two one-inch plates 1861 00:35:34,320 --> 00:35:36,230 and it's made up of two one-inch plates and you're wanting to hold them together 1862 00:35:36,230 --> 00:35:36,240 and you're wanting to hold them together 1863 00:35:36,240 --> 00:35:38,870 and you're wanting to hold them together with bolts and you're going to have uh 1864 00:35:38,870 --> 00:35:38,880 with bolts and you're going to have uh 1865 00:35:38,880 --> 00:35:40,630 with bolts and you're going to have uh two two at a 1866 00:35:40,630 --> 00:35:40,640 two two at a 1867 00:35:40,640 --> 00:35:42,710 two two at a at each spot so you want to know how far 1868 00:35:42,710 --> 00:35:42,720 at each spot so you want to know how far 1869 00:35:42,720 --> 00:35:46,230 at each spot so you want to know how far apart your rose bolts need to be 1870 00:35:46,230 --> 00:35:46,240 apart your rose bolts need to be 1871 00:35:46,240 --> 00:35:48,230 apart your rose bolts need to be how far can you go and still hold the 1872 00:35:48,230 --> 00:35:48,240 how far can you go and still hold the 1873 00:35:48,240 --> 00:35:50,550 how far can you go and still hold the thing together 1874 00:35:50,550 --> 00:35:50,560 thing together 1875 00:35:50,560 --> 00:35:52,230 thing together so 1876 00:35:52,230 --> 00:35:52,240 so 1877 00:35:52,240 --> 00:35:55,430 so that's this e is the spacing here 1878 00:35:55,430 --> 00:35:55,440 that's this e is the spacing here 1879 00:35:55,440 --> 00:35:56,870 that's this e is the spacing here because you see what you actually get 1880 00:35:56,870 --> 00:35:56,880 because you see what you actually get 1881 00:35:56,880 --> 00:35:58,790 because you see what you actually get when you apply the moment 1882 00:35:58,790 --> 00:35:58,800 when you apply the moment 1883 00:35:58,800 --> 00:36:00,230 when you apply the moment then you have the horizontal shear 1884 00:36:00,230 --> 00:36:00,240 then you have the horizontal shear 1885 00:36:00,240 --> 00:36:01,910 then you have the horizontal shear surface here which in this case is the 1886 00:36:01,910 --> 00:36:01,920 surface here which in this case is the 1887 00:36:01,920 --> 00:36:03,910 surface here which in this case is the neutral axis of the beam 1888 00:36:03,910 --> 00:36:03,920 neutral axis of the beam 1889 00:36:03,920 --> 00:36:06,870 neutral axis of the beam and you need to calculate that stress 1890 00:36:06,870 --> 00:36:06,880 and you need to calculate that stress 1891 00:36:06,880 --> 00:36:08,790 and you need to calculate that stress and determine the bolts 1892 00:36:08,790 --> 00:36:08,800 and determine the bolts 1893 00:36:08,800 --> 00:36:10,390 and determine the bolts all right 1894 00:36:10,390 --> 00:36:10,400 all right 1895 00:36:10,400 --> 00:36:12,630 all right you get the reactions 1896 00:36:12,630 --> 00:36:12,640 you get the reactions 1897 00:36:12,640 --> 00:36:14,710 you get the reactions to the beam 1898 00:36:14,710 --> 00:36:14,720 to the beam 1899 00:36:14,720 --> 00:36:17,349 to the beam and then you get the moment 1900 00:36:17,349 --> 00:36:17,359 and then you get the moment 1901 00:36:17,359 --> 00:36:19,510 and then you get the moment it's a uniformly loaded beam so it's wl 1902 00:36:19,510 --> 00:36:19,520 it's a uniformly loaded beam so it's wl 1903 00:36:19,520 --> 00:36:21,349 it's a uniformly loaded beam so it's wl squared over eight 1904 00:36:21,349 --> 00:36:21,359 squared over eight 1905 00:36:21,359 --> 00:36:23,190 squared over eight and then 1906 00:36:23,190 --> 00:36:23,200 and then 1907 00:36:23,200 --> 00:36:25,349 and then you determine a value here because you 1908 00:36:25,349 --> 00:36:25,359 you determine a value here because you 1909 00:36:25,359 --> 00:36:26,870 you determine a value here because you also have to check bending stress to 1910 00:36:26,870 --> 00:36:26,880 also have to check bending stress to 1911 00:36:26,880 --> 00:36:28,230 also have to check bending stress to make sure that your bending stress is 1912 00:36:28,230 --> 00:36:28,240 make sure that your bending stress is 1913 00:36:28,240 --> 00:36:30,150 make sure that your bending stress is all right even if you do carry it carry 1914 00:36:30,150 --> 00:36:30,160 all right even if you do carry it carry 1915 00:36:30,160 --> 00:36:32,069 all right even if you do carry it carry the shear still has to hold it in 1916 00:36:32,069 --> 00:36:32,079 the shear still has to hold it in 1917 00:36:32,079 --> 00:36:33,670 the shear still has to hold it in bending 1918 00:36:33,670 --> 00:36:33,680 bending 1919 00:36:33,680 --> 00:36:35,190 bending so 1920 00:36:35,190 --> 00:36:35,200 so 1921 00:36:35,200 --> 00:36:37,589 so i just took a guess at the diameter bolt 1922 00:36:37,589 --> 00:36:37,599 i just took a guess at the diameter bolt 1923 00:36:37,599 --> 00:36:39,270 i just took a guess at the diameter bolt and said well i'll use a half inch bolt 1924 00:36:39,270 --> 00:36:39,280 and said well i'll use a half inch bolt 1925 00:36:39,280 --> 00:36:40,790 and said well i'll use a half inch bolt in this and see how it works out and 1926 00:36:40,790 --> 00:36:40,800 in this and see how it works out and 1927 00:36:40,800 --> 00:36:42,470 in this and see how it works out and then i'll calculate it 1928 00:36:42,470 --> 00:36:42,480 then i'll calculate it 1929 00:36:42,480 --> 00:36:45,990 then i'll calculate it so if you go into this the v q over ib 1930 00:36:45,990 --> 00:36:46,000 so if you go into this the v q over ib 1931 00:36:46,000 --> 00:36:46,950 so if you go into this the v q over ib remember 1932 00:36:46,950 --> 00:36:46,960 remember 1933 00:36:46,960 --> 00:36:47,670 remember the 1934 00:36:47,670 --> 00:36:47,680 the 1935 00:36:47,680 --> 00:36:50,390 the v is the vertical shear at the point 1936 00:36:50,390 --> 00:36:50,400 v is the vertical shear at the point 1937 00:36:50,400 --> 00:36:51,109 v is the vertical shear at the point q 1938 00:36:51,109 --> 00:36:51,119 q 1939 00:36:51,119 --> 00:36:54,390 q is the what's called the statical moment 1940 00:36:54,390 --> 00:36:54,400 is the what's called the statical moment 1941 00:36:54,400 --> 00:36:57,510 is the what's called the statical moment which is the area above which you're 1942 00:36:57,510 --> 00:36:57,520 which is the area above which you're 1943 00:36:57,520 --> 00:36:58,950 which is the area above which you're wanting to 1944 00:36:58,950 --> 00:36:58,960 wanting to 1945 00:36:58,960 --> 00:37:01,510 wanting to check the stress above that shear plane 1946 00:37:01,510 --> 00:37:01,520 check the stress above that shear plane 1947 00:37:01,520 --> 00:37:02,550 check the stress above that shear plane times 1948 00:37:02,550 --> 00:37:02,560 times 1949 00:37:02,560 --> 00:37:05,349 times the distance to its centroid 1950 00:37:05,349 --> 00:37:05,359 the distance to its centroid 1951 00:37:05,359 --> 00:37:07,829 the distance to its centroid that's a statical moment 1952 00:37:07,829 --> 00:37:07,839 that's a statical moment 1953 00:37:07,839 --> 00:37:11,670 that's a statical moment then so so the q here was the 1954 00:37:11,670 --> 00:37:11,680 then so so the q here was the 1955 00:37:11,680 --> 00:37:14,310 then so so the q here was the i calculated was was three three inches 1956 00:37:14,310 --> 00:37:14,320 i calculated was was three three inches 1957 00:37:14,320 --> 00:37:15,910 i calculated was was three three inches uh cubed 1958 00:37:15,910 --> 00:37:15,920 uh cubed 1959 00:37:15,920 --> 00:37:17,829 uh cubed because it is a 1960 00:37:17,829 --> 00:37:17,839 because it is a 1961 00:37:17,839 --> 00:37:20,150 because it is a area times the distance so which makes 1962 00:37:20,150 --> 00:37:20,160 area times the distance so which makes 1963 00:37:20,160 --> 00:37:21,589 area times the distance so which makes it cubed 1964 00:37:21,589 --> 00:37:21,599 it cubed 1965 00:37:21,599 --> 00:37:23,190 it cubed then you go in and calculate the moment 1966 00:37:23,190 --> 00:37:23,200 then you go in and calculate the moment 1967 00:37:23,200 --> 00:37:25,430 then you go in and calculate the moment of inertia in this case i left out the 1968 00:37:25,430 --> 00:37:25,440 of inertia in this case i left out the 1969 00:37:25,440 --> 00:37:27,510 of inertia in this case i left out the diameter of the holes on this because i 1970 00:37:27,510 --> 00:37:27,520 diameter of the holes on this because i 1971 00:37:27,520 --> 00:37:31,190 diameter of the holes on this because i was just doing it rough 1972 00:37:31,190 --> 00:37:31,200 1973 00:37:31,200 --> 00:37:33,109 and of course one of the things you that 1974 00:37:33,109 --> 00:37:33,119 and of course one of the things you that 1975 00:37:33,119 --> 00:37:35,430 and of course one of the things you that you should do in the final calculations 1976 00:37:35,430 --> 00:37:35,440 you should do in the final calculations 1977 00:37:35,440 --> 00:37:37,750 you should do in the final calculations you actually deduct for the diameter of 1978 00:37:37,750 --> 00:37:37,760 you actually deduct for the diameter of 1979 00:37:37,760 --> 00:37:39,589 you actually deduct for the diameter of the holes in order to get the proper 1980 00:37:39,589 --> 00:37:39,599 the holes in order to get the proper 1981 00:37:39,599 --> 00:37:42,069 the holes in order to get the proper moment of inertia 1982 00:37:42,069 --> 00:37:42,079 moment of inertia 1983 00:37:42,079 --> 00:37:44,550 moment of inertia then i went in and said for no 1984 00:37:44,550 --> 00:37:44,560 then i went in and said for no 1985 00:37:44,560 --> 00:37:46,710 then i went in and said for no bolt hole reduction 1986 00:37:46,710 --> 00:37:46,720 bolt hole reduction 1987 00:37:46,720 --> 00:37:48,829 bolt hole reduction i'll have this 1988 00:37:48,829 --> 00:37:48,839 i'll have this 1989 00:37:48,839 --> 00:37:51,589 i'll have this stress now that'll be across that shaded 1990 00:37:51,589 --> 00:37:51,599 stress now that'll be across that shaded 1991 00:37:51,599 --> 00:37:53,750 stress now that'll be across that shaded area back in the figure there 1992 00:37:53,750 --> 00:37:53,760 area back in the figure there 1993 00:37:53,760 --> 00:37:57,190 area back in the figure there which was six wide so it was six e so i 1994 00:37:57,190 --> 00:37:57,200 which was six wide so it was six e so i 1995 00:37:57,200 --> 00:37:58,710 which was six wide so it was six e so i saw for 1996 00:37:58,710 --> 00:37:58,720 saw for 1997 00:37:58,720 --> 00:37:59,589 saw for the 1998 00:37:59,589 --> 00:37:59,599 the 1999 00:37:59,599 --> 00:38:01,990 the number of pounds that i would have that 2000 00:38:01,990 --> 00:38:02,000 number of pounds that i would have that 2001 00:38:02,000 --> 00:38:04,470 number of pounds that i would have that i'd have to react at that point all 2002 00:38:04,470 --> 00:38:04,480 i'd have to react at that point all 2003 00:38:04,480 --> 00:38:07,109 i'd have to react at that point all right if i take two half inch diameter 2004 00:38:07,109 --> 00:38:07,119 right if i take two half inch diameter 2005 00:38:07,119 --> 00:38:08,870 right if i take two half inch diameter grade five bolts good for about ten 2006 00:38:08,870 --> 00:38:08,880 grade five bolts good for about ten 2007 00:38:08,880 --> 00:38:11,190 grade five bolts good for about ten thousand five hundred pounds a piece and 2008 00:38:11,190 --> 00:38:11,200 thousand five hundred pounds a piece and 2009 00:38:11,200 --> 00:38:12,950 thousand five hundred pounds a piece and i'd divide 2010 00:38:12,950 --> 00:38:12,960 i'd divide 2011 00:38:12,960 --> 00:38:15,670 i'd divide this total load into that and solve for 2012 00:38:15,670 --> 00:38:15,680 this total load into that and solve for 2013 00:38:15,680 --> 00:38:18,550 this total load into that and solve for e i get 2.8 inches maximum spacing 2014 00:38:18,550 --> 00:38:18,560 e i get 2.8 inches maximum spacing 2015 00:38:18,560 --> 00:38:21,109 e i get 2.8 inches maximum spacing between row of bolts 2016 00:38:21,109 --> 00:38:21,119 between row of bolts 2017 00:38:21,119 --> 00:38:22,230 between row of bolts so 2018 00:38:22,230 --> 00:38:22,240 so 2019 00:38:22,240 --> 00:38:24,870 so then i went back and said okay i'll use 2020 00:38:24,870 --> 00:38:24,880 then i went back and said okay i'll use 2021 00:38:24,880 --> 00:38:26,790 then i went back and said okay i'll use 9 16 bolts 2022 00:38:26,790 --> 00:38:26,800 9 16 bolts 2023 00:38:26,800 --> 00:38:28,630 9 16 bolts and with with a clearance hole and now 2024 00:38:28,630 --> 00:38:28,640 and with with a clearance hole and now 2025 00:38:28,640 --> 00:38:31,270 and with with a clearance hole and now i'll deduct for the 2026 00:38:31,270 --> 00:38:31,280 i'll deduct for the 2027 00:38:31,280 --> 00:38:33,829 i'll deduct for the holes that i'm taking out 2028 00:38:33,829 --> 00:38:33,839 holes that i'm taking out 2029 00:38:33,839 --> 00:38:35,030 holes that i'm taking out and 2030 00:38:35,030 --> 00:38:35,040 and 2031 00:38:35,040 --> 00:38:36,710 and calculate a new i 2032 00:38:36,710 --> 00:38:36,720 calculate a new i 2033 00:38:36,720 --> 00:38:38,950 calculate a new i and then go in and calculate the 2034 00:38:38,950 --> 00:38:38,960 and then go in and calculate the 2035 00:38:38,960 --> 00:38:41,990 and then go in and calculate the shearing stress take that to get me a 2036 00:38:41,990 --> 00:38:42,000 shearing stress take that to get me a 2037 00:38:42,000 --> 00:38:45,270 shearing stress take that to get me a value involving e and then solve for e 2038 00:38:45,270 --> 00:38:45,280 value involving e and then solve for e 2039 00:38:45,280 --> 00:38:47,190 value involving e and then solve for e using the higher allowables for the 9 16 2040 00:38:47,190 --> 00:38:47,200 using the higher allowables for the 9 16 2041 00:38:47,200 --> 00:38:49,430 using the higher allowables for the 9 16 bolts and i get 2.94 inches for row 2042 00:38:49,430 --> 00:38:49,440 bolts and i get 2.94 inches for row 2043 00:38:49,440 --> 00:38:52,710 bolts and i get 2.94 inches for row spacing now you could optimize on that 2044 00:38:52,710 --> 00:38:52,720 spacing now you could optimize on that 2045 00:38:52,720 --> 00:38:54,470 spacing now you could optimize on that and do all sorts of things but what i 2046 00:38:54,470 --> 00:38:54,480 and do all sorts of things but what i 2047 00:38:54,480 --> 00:38:57,109 and do all sorts of things but what i was interested in here 2048 00:38:57,109 --> 00:38:57,119 was interested in here 2049 00:38:57,119 --> 00:38:58,150 was interested in here was just 2050 00:38:58,150 --> 00:38:58,160 was just 2051 00:38:58,160 --> 00:39:00,550 was just showing how you would do it 2052 00:39:00,550 --> 00:39:00,560 showing how you would do it 2053 00:39:00,560 --> 00:39:03,589 showing how you would do it because uh none of the books that i had 2054 00:39:03,589 --> 00:39:03,599 because uh none of the books that i had 2055 00:39:03,599 --> 00:39:05,430 because uh none of the books that i had actually strength material books showed 2056 00:39:05,430 --> 00:39:05,440 actually strength material books showed 2057 00:39:05,440 --> 00:39:07,589 actually strength material books showed that the way it was supposed to be i 2058 00:39:07,589 --> 00:39:07,599 that the way it was supposed to be i 2059 00:39:07,599 --> 00:39:10,470 that the way it was supposed to be i didn't think so 2060 00:39:10,470 --> 00:39:10,480 2061 00:39:10,480 --> 00:39:12,230 now you still have to go in and check 2062 00:39:12,230 --> 00:39:12,240 now you still have to go in and check 2063 00:39:12,240 --> 00:39:14,150 now you still have to go in and check for beam bending and bearing stress 2064 00:39:14,150 --> 00:39:14,160 for beam bending and bearing stress 2065 00:39:14,160 --> 00:39:16,390 for beam bending and bearing stress calculations 2066 00:39:16,390 --> 00:39:16,400 calculations 2067 00:39:16,400 --> 00:39:17,349 calculations and 2068 00:39:17,349 --> 00:39:17,359 and 2069 00:39:17,359 --> 00:39:19,349 and notice also that 2070 00:39:19,349 --> 00:39:19,359 notice also that 2071 00:39:19,359 --> 00:39:21,349 notice also that thin structures would have to be checked 2072 00:39:21,349 --> 00:39:21,359 thin structures would have to be checked 2073 00:39:21,359 --> 00:39:23,910 thin structures would have to be checked for inner rivet buckling because if you 2074 00:39:23,910 --> 00:39:23,920 for inner rivet buckling because if you 2075 00:39:23,920 --> 00:39:24,870 for inner rivet buckling because if you have 2076 00:39:24,870 --> 00:39:24,880 have 2077 00:39:24,880 --> 00:39:26,550 have thin sheet 2078 00:39:26,550 --> 00:39:26,560 thin sheet 2079 00:39:26,560 --> 00:39:28,630 thin sheet and your fasteners are spaced too far 2080 00:39:28,630 --> 00:39:28,640 and your fasteners are spaced too far 2081 00:39:28,640 --> 00:39:31,510 and your fasteners are spaced too far apart the sheet can buckle in between 2082 00:39:31,510 --> 00:39:31,520 apart the sheet can buckle in between 2083 00:39:31,520 --> 00:39:34,069 apart the sheet can buckle in between fasteners under compressive load 2084 00:39:34,069 --> 00:39:34,079 fasteners under compressive load 2085 00:39:34,079 --> 00:39:35,750 fasteners under compressive load and 2086 00:39:35,750 --> 00:39:35,760 and 2087 00:39:35,760 --> 00:39:36,950 and i 2088 00:39:36,950 --> 00:39:36,960 i 2089 00:39:36,960 --> 00:39:38,310 i you've heard that statement about a 2090 00:39:38,310 --> 00:39:38,320 you've heard that statement about a 2091 00:39:38,320 --> 00:39:40,230 you've heard that statement about a little knowledge is a dangerous thing i 2092 00:39:40,230 --> 00:39:40,240 little knowledge is a dangerous thing i 2093 00:39:40,240 --> 00:39:41,190 little knowledge is a dangerous thing i was 2094 00:39:41,190 --> 00:39:41,200 was 2095 00:39:41,200 --> 00:39:43,030 was telling a guy that this could happen one 2096 00:39:43,030 --> 00:39:43,040 telling a guy that this could happen one 2097 00:39:43,040 --> 00:39:44,710 telling a guy that this could happen one time at martin and he was taking 2098 00:39:44,710 --> 00:39:44,720 time at martin and he was taking 2099 00:39:44,720 --> 00:39:47,510 time at martin and he was taking strength materials so he said nah 2100 00:39:47,510 --> 00:39:47,520 strength materials so he said nah 2101 00:39:47,520 --> 00:39:48,470 strength materials so he said nah that 2102 00:39:48,470 --> 00:39:48,480 that 2103 00:39:48,480 --> 00:39:50,069 that that can't happen 2104 00:39:50,069 --> 00:39:50,079 that can't happen 2105 00:39:50,079 --> 00:39:51,829 that can't happen so i went to see one of the old-timers 2106 00:39:51,829 --> 00:39:51,839 so i went to see one of the old-timers 2107 00:39:51,839 --> 00:39:54,150 so i went to see one of the old-timers to find out how to get out of it and he 2108 00:39:54,150 --> 00:39:54,160 to find out how to get out of it and he 2109 00:39:54,160 --> 00:39:55,030 to find out how to get out of it and he said 2110 00:39:55,030 --> 00:39:55,040 said 2111 00:39:55,040 --> 00:39:56,950 said well just go up and tear a page out of 2112 00:39:56,950 --> 00:39:56,960 well just go up and tear a page out of 2113 00:39:56,960 --> 00:39:58,790 well just go up and tear a page out of his notebook that'll prove the point 2114 00:39:58,790 --> 00:39:58,800 his notebook that'll prove the point 2115 00:39:58,800 --> 00:40:01,510 his notebook that'll prove the point because you see if you take a page 2116 00:40:01,510 --> 00:40:01,520 because you see if you take a page 2117 00:40:01,520 --> 00:40:02,870 because you see if you take a page and you pull it 2118 00:40:02,870 --> 00:40:02,880 and you pull it 2119 00:40:02,880 --> 00:40:04,710 and you pull it this way 2120 00:40:04,710 --> 00:40:04,720 this way 2121 00:40:04,720 --> 00:40:07,589 this way the sheet will buckle between holes 2122 00:40:07,589 --> 00:40:07,599 the sheet will buckle between holes 2123 00:40:07,599 --> 00:40:09,750 the sheet will buckle between holes before it tears up 2124 00:40:09,750 --> 00:40:09,760 before it tears up 2125 00:40:09,760 --> 00:40:11,589 before it tears up so so i did that never had any more 2126 00:40:11,589 --> 00:40:11,599 so so i did that never had any more 2127 00:40:11,599 --> 00:40:13,270 so so i did that never had any more trouble with the guy he went back to 2128 00:40:13,270 --> 00:40:13,280 trouble with the guy he went back to 2129 00:40:13,280 --> 00:40:15,750 trouble with the guy he went back to strength materials book 2130 00:40:15,750 --> 00:40:15,760 strength materials book 2131 00:40:15,760 --> 00:40:17,430 strength materials book so 2132 00:40:17,430 --> 00:40:17,440 so 2133 00:40:17,440 --> 00:40:19,589 so so that's how to cut to carry the 2134 00:40:19,589 --> 00:40:19,599 so that's how to cut to carry the 2135 00:40:19,599 --> 00:40:22,710 so that's how to cut to carry the horizontal shear loads now we go into 2136 00:40:22,710 --> 00:40:22,720 horizontal shear loads now we go into 2137 00:40:22,720 --> 00:40:25,750 horizontal shear loads now we go into bolded flanges with o-rings now granted 2138 00:40:25,750 --> 00:40:25,760 bolded flanges with o-rings now granted 2139 00:40:25,760 --> 00:40:28,870 bolded flanges with o-rings now granted that is a science within itself 2140 00:40:28,870 --> 00:40:28,880 that is a science within itself 2141 00:40:28,880 --> 00:40:29,670 that is a science within itself but 2142 00:40:29,670 --> 00:40:29,680 but 2143 00:40:29,680 --> 00:40:32,470 but we'll cover it here just to let you know 2144 00:40:32,470 --> 00:40:32,480 we'll cover it here just to let you know 2145 00:40:32,480 --> 00:40:34,470 we'll cover it here just to let you know that you have to 2146 00:40:34,470 --> 00:40:34,480 that you have to 2147 00:40:34,480 --> 00:40:37,109 that you have to do this with bolted joints 2148 00:40:37,109 --> 00:40:37,119 do this with bolted joints 2149 00:40:37,119 --> 00:40:39,589 do this with bolted joints uh o-ring compression 2150 00:40:39,589 --> 00:40:39,599 uh o-ring compression 2151 00:40:39,599 --> 00:40:41,349 uh o-ring compression in a flange is 2152 00:40:41,349 --> 00:40:41,359 in a flange is 2153 00:40:41,359 --> 00:40:43,750 in a flange is usually just a small portion of the 2154 00:40:43,750 --> 00:40:43,760 usually just a small portion of the 2155 00:40:43,760 --> 00:40:45,270 usually just a small portion of the total bolt load 2156 00:40:45,270 --> 00:40:45,280 total bolt load 2157 00:40:45,280 --> 00:40:47,510 total bolt load and of course the o-ring groove is sized 2158 00:40:47,510 --> 00:40:47,520 and of course the o-ring groove is sized 2159 00:40:47,520 --> 00:40:51,270 and of course the o-ring groove is sized to give a specific range of compression 2160 00:40:51,270 --> 00:40:51,280 to give a specific range of compression 2161 00:40:51,280 --> 00:40:53,670 to give a specific range of compression on it when you go metal to metal on the 2162 00:40:53,670 --> 00:40:53,680 on it when you go metal to metal on the 2163 00:40:53,680 --> 00:40:55,030 on it when you go metal to metal on the flanges 2164 00:40:55,030 --> 00:40:55,040 flanges 2165 00:40:55,040 --> 00:40:57,589 flanges now for most o-rings this compression 2166 00:40:57,589 --> 00:40:57,599 now for most o-rings this compression 2167 00:40:57,599 --> 00:40:58,870 now for most o-rings this compression value is like 2168 00:40:58,870 --> 00:40:58,880 value is like 2169 00:40:58,880 --> 00:41:01,270 value is like a minimum of 10 to a maximum of about 30 2170 00:41:01,270 --> 00:41:01,280 a minimum of 10 to a maximum of about 30 2171 00:41:01,280 --> 00:41:03,829 a minimum of 10 to a maximum of about 30 percent of the unloaded cross-section 2172 00:41:03,829 --> 00:41:03,839 percent of the unloaded cross-section 2173 00:41:03,839 --> 00:41:05,430 percent of the unloaded cross-section diameter 2174 00:41:05,430 --> 00:41:05,440 diameter 2175 00:41:05,440 --> 00:41:07,510 diameter and of course the flange surfaces have 2176 00:41:07,510 --> 00:41:07,520 and of course the flange surfaces have 2177 00:41:07,520 --> 00:41:10,550 and of course the flange surfaces have to be smooth to assure ceiling without 2178 00:41:10,550 --> 00:41:10,560 to be smooth to assure ceiling without 2179 00:41:10,560 --> 00:41:12,710 to be smooth to assure ceiling without tearing up the o-ring 2180 00:41:12,710 --> 00:41:12,720 tearing up the o-ring 2181 00:41:12,720 --> 00:41:14,870 tearing up the o-ring and the fastener spacing must be close 2182 00:41:14,870 --> 00:41:14,880 and the fastener spacing must be close 2183 00:41:14,880 --> 00:41:16,230 and the fastener spacing must be close enough to keep the flanges from 2184 00:41:16,230 --> 00:41:16,240 enough to keep the flanges from 2185 00:41:16,240 --> 00:41:17,670 enough to keep the flanges from separating that's one of the things you 2186 00:41:17,670 --> 00:41:17,680 separating that's one of the things you 2187 00:41:17,680 --> 00:41:19,829 separating that's one of the things you have to watch about now granted in most 2188 00:41:19,829 --> 00:41:19,839 have to watch about now granted in most 2189 00:41:19,839 --> 00:41:21,510 have to watch about now granted in most cases it's not a 2190 00:41:21,510 --> 00:41:21,520 cases it's not a 2191 00:41:21,520 --> 00:41:22,470 cases it's not a problem 2192 00:41:22,470 --> 00:41:22,480 problem 2193 00:41:22,480 --> 00:41:24,230 problem and of course the 2194 00:41:24,230 --> 00:41:24,240 and of course the 2195 00:41:24,240 --> 00:41:26,710 and of course the this has uh just a general design 2196 00:41:26,710 --> 00:41:26,720 this has uh just a general design 2197 00:41:26,720 --> 00:41:28,069 this has uh just a general design practice 2198 00:41:28,069 --> 00:41:28,079 practice 2199 00:41:28,079 --> 00:41:29,829 practice you machine the o-ring groove in the 2200 00:41:29,829 --> 00:41:29,839 you machine the o-ring groove in the 2201 00:41:29,839 --> 00:41:32,309 you machine the o-ring groove in the cheaper the two mating flanges 2202 00:41:32,309 --> 00:41:32,319 cheaper the two mating flanges 2203 00:41:32,319 --> 00:41:34,710 cheaper the two mating flanges because if the machine is uh 2204 00:41:34,710 --> 00:41:34,720 because if the machine is uh 2205 00:41:34,720 --> 00:41:36,230 because if the machine is uh if the machinist cuts the groove too 2206 00:41:36,230 --> 00:41:36,240 if the machinist cuts the groove too 2207 00:41:36,240 --> 00:41:38,470 if the machinist cuts the groove too deep the parts scrap 2208 00:41:38,470 --> 00:41:38,480 deep the parts scrap 2209 00:41:38,480 --> 00:41:39,910 deep the parts scrap so you want to make sure that it's in 2210 00:41:39,910 --> 00:41:39,920 so you want to make sure that it's in 2211 00:41:39,920 --> 00:41:42,710 so you want to make sure that it's in the cheaper the two flanges and so you 2212 00:41:42,710 --> 00:41:42,720 the cheaper the two flanges and so you 2213 00:41:42,720 --> 00:41:44,710 the cheaper the two flanges and so you can throw it away if you need to 2214 00:41:44,710 --> 00:41:44,720 can throw it away if you need to 2215 00:41:44,720 --> 00:41:49,190 can throw it away if you need to and if you need a dovetail groove 2216 00:41:49,190 --> 00:41:49,200 and if you need a dovetail groove 2217 00:41:49,200 --> 00:41:50,790 and if you need a dovetail groove to hold the o-ring in place during 2218 00:41:50,790 --> 00:41:50,800 to hold the o-ring in place during 2219 00:41:50,800 --> 00:41:53,349 to hold the o-ring in place during assembly disassembly that also can be 2220 00:41:53,349 --> 00:41:53,359 assembly disassembly that also can be 2221 00:41:53,359 --> 00:41:54,950 assembly disassembly that also can be machined in 2222 00:41:54,950 --> 00:41:54,960 machined in 2223 00:41:54,960 --> 00:41:56,470 machined in now here is 2224 00:41:56,470 --> 00:41:56,480 now here is 2225 00:41:56,480 --> 00:41:58,069 now here is a generic 2226 00:41:58,069 --> 00:41:58,079 a generic 2227 00:41:58,079 --> 00:42:01,109 a generic o-ring joint 2228 00:42:01,109 --> 00:42:01,119 2229 00:42:01,119 --> 00:42:02,390 and uh 2230 00:42:02,390 --> 00:42:02,400 and uh 2231 00:42:02,400 --> 00:42:05,430 and uh the uh 2232 00:42:05,430 --> 00:42:05,440 2233 00:42:05,440 --> 00:42:08,550 there's the the o-ring normally the 2234 00:42:08,550 --> 00:42:08,560 there's the the o-ring normally the 2235 00:42:08,560 --> 00:42:10,710 there's the the o-ring normally the the only thing you got to worry about is 2236 00:42:10,710 --> 00:42:10,720 the only thing you got to worry about is 2237 00:42:10,720 --> 00:42:12,470 the only thing you got to worry about is having a smooth enough finish on this 2238 00:42:12,470 --> 00:42:12,480 having a smooth enough finish on this 2239 00:42:12,480 --> 00:42:14,790 having a smooth enough finish on this mating surface in that area that it 2240 00:42:14,790 --> 00:42:14,800 mating surface in that area that it 2241 00:42:14,800 --> 00:42:17,109 mating surface in that area that it doesn't chew up the o-ring 2242 00:42:17,109 --> 00:42:17,119 doesn't chew up the o-ring 2243 00:42:17,119 --> 00:42:19,109 doesn't chew up the o-ring and have enough fasteners to keep the 2244 00:42:19,109 --> 00:42:19,119 and have enough fasteners to keep the 2245 00:42:19,119 --> 00:42:23,030 and have enough fasteners to keep the flanges metal to metal 2246 00:42:23,030 --> 00:42:23,040 2247 00:42:23,040 --> 00:42:25,030 now if you go to bolted flanges with 2248 00:42:25,030 --> 00:42:25,040 now if you go to bolted flanges with 2249 00:42:25,040 --> 00:42:27,510 now if you go to bolted flanges with flat gaskets 2250 00:42:27,510 --> 00:42:27,520 flat gaskets 2251 00:42:27,520 --> 00:42:30,710 flat gaskets then you got a another problem 2252 00:42:30,710 --> 00:42:30,720 then you got a another problem 2253 00:42:30,720 --> 00:42:33,750 then you got a another problem you need to squeeze the gasket to seal 2254 00:42:33,750 --> 00:42:33,760 you need to squeeze the gasket to seal 2255 00:42:33,760 --> 00:42:34,390 you need to squeeze the gasket to seal it 2256 00:42:34,390 --> 00:42:34,400 it 2257 00:42:34,400 --> 00:42:36,630 it but on the other hand you don't want to 2258 00:42:36,630 --> 00:42:36,640 but on the other hand you don't want to 2259 00:42:36,640 --> 00:42:38,870 but on the other hand you don't want to squeeze it so much 2260 00:42:38,870 --> 00:42:38,880 squeeze it so much 2261 00:42:38,880 --> 00:42:41,670 squeeze it so much that you uh yield it in compression and 2262 00:42:41,670 --> 00:42:41,680 that you uh yield it in compression and 2263 00:42:41,680 --> 00:42:43,430 that you uh yield it in compression and ruin it 2264 00:42:43,430 --> 00:42:43,440 ruin it 2265 00:42:43,440 --> 00:42:46,790 ruin it so so now you have to look harder at the 2266 00:42:46,790 --> 00:42:46,800 so so now you have to look harder at the 2267 00:42:46,800 --> 00:42:48,230 so so now you have to look harder at the amount of load that you're putting in 2268 00:42:48,230 --> 00:42:48,240 amount of load that you're putting in 2269 00:42:48,240 --> 00:42:49,589 amount of load that you're putting in with your bolts 2270 00:42:49,589 --> 00:42:49,599 with your bolts 2271 00:42:49,599 --> 00:42:51,990 with your bolts now a lot of gasket manufacturers would 2272 00:42:51,990 --> 00:42:52,000 now a lot of gasket manufacturers would 2273 00:42:52,000 --> 00:42:54,069 now a lot of gasket manufacturers would give you a 2274 00:42:54,069 --> 00:42:54,079 give you a 2275 00:42:54,079 --> 00:42:56,230 give you a pounds per linear inch or something for 2276 00:42:56,230 --> 00:42:56,240 pounds per linear inch or something for 2277 00:42:56,240 --> 00:42:58,630 pounds per linear inch or something for a flat gasket so that you know them by 2278 00:42:58,630 --> 00:42:58,640 a flat gasket so that you know them by 2279 00:42:58,640 --> 00:43:00,870 a flat gasket so that you know them by your bolt spacing how much you need to 2280 00:43:00,870 --> 00:43:00,880 your bolt spacing how much you need to 2281 00:43:00,880 --> 00:43:03,829 your bolt spacing how much you need to put in to get the thing to seal 2282 00:43:03,829 --> 00:43:03,839 put in to get the thing to seal 2283 00:43:03,839 --> 00:43:05,670 put in to get the thing to seal at least that gives you a minimum load 2284 00:43:05,670 --> 00:43:05,680 at least that gives you a minimum load 2285 00:43:05,680 --> 00:43:07,829 at least that gives you a minimum load that you have to have and then then of 2286 00:43:07,829 --> 00:43:07,839 that you have to have and then then of 2287 00:43:07,839 --> 00:43:09,589 that you have to have and then then of course you have to look at the 2288 00:43:09,589 --> 00:43:09,599 course you have to look at the 2289 00:43:09,599 --> 00:43:12,069 course you have to look at the compressive yield of the gasket to see 2290 00:43:12,069 --> 00:43:12,079 compressive yield of the gasket to see 2291 00:43:12,079 --> 00:43:13,990 compressive yield of the gasket to see whether you're putting too much load in 2292 00:43:13,990 --> 00:43:14,000 whether you're putting too much load in 2293 00:43:14,000 --> 00:43:15,270 whether you're putting too much load in or not 2294 00:43:15,270 --> 00:43:15,280 or not 2295 00:43:15,280 --> 00:43:16,069 or not so 2296 00:43:16,069 --> 00:43:16,079 so 2297 00:43:16,079 --> 00:43:17,990 so usually the best thing to do on that is 2298 00:43:17,990 --> 00:43:18,000 usually the best thing to do on that is 2299 00:43:18,000 --> 00:43:19,190 usually the best thing to do on that is is get the information from the 2300 00:43:19,190 --> 00:43:19,200 is get the information from the 2301 00:43:19,200 --> 00:43:20,950 is get the information from the manufacturers because they they know 2302 00:43:20,950 --> 00:43:20,960 manufacturers because they they know 2303 00:43:20,960 --> 00:43:23,030 manufacturers because they they know their their product well enough to give 2304 00:43:23,030 --> 00:43:23,040 their their product well enough to give 2305 00:43:23,040 --> 00:43:25,190 their their product well enough to give you the 2306 00:43:25,190 --> 00:43:25,200 you the 2307 00:43:25,200 --> 00:43:27,750 you the the proper values that you can use 2308 00:43:27,750 --> 00:43:27,760 the proper values that you can use 2309 00:43:27,760 --> 00:43:29,270 the proper values that you can use and of course 2310 00:43:29,270 --> 00:43:29,280 and of course 2311 00:43:29,280 --> 00:43:32,870 and of course we'll have some things in subsequent 2312 00:43:32,870 --> 00:43:32,880 we'll have some things in subsequent 2313 00:43:32,880 --> 00:43:34,710 we'll have some things in subsequent sections on 2314 00:43:34,710 --> 00:43:34,720 sections on 2315 00:43:34,720 --> 00:43:36,069 sections on what to do 2316 00:43:36,069 --> 00:43:36,079 what to do 2317 00:43:36,079 --> 00:43:39,430 what to do where you have gaps on flanges now 2318 00:43:39,430 --> 00:43:39,440 where you have gaps on flanges now 2319 00:43:39,440 --> 00:43:43,030 where you have gaps on flanges now here's a regular flat gasket 2320 00:43:43,030 --> 00:43:43,040 here's a regular flat gasket 2321 00:43:43,040 --> 00:43:44,630 here's a regular flat gasket joint 2322 00:43:44,630 --> 00:43:44,640 joint 2323 00:43:44,640 --> 00:43:45,589 joint and 2324 00:43:45,589 --> 00:43:45,599 and 2325 00:43:45,599 --> 00:43:47,030 and one of the things you normally do with 2326 00:43:47,030 --> 00:43:47,040 one of the things you normally do with 2327 00:43:47,040 --> 00:43:49,990 one of the things you normally do with gaskets too if you're in 2328 00:43:49,990 --> 00:43:50,000 gaskets too if you're in 2329 00:43:50,000 --> 00:43:51,829 gaskets too if you're in the automotive world you use some sort 2330 00:43:51,829 --> 00:43:51,839 the automotive world you use some sort 2331 00:43:51,839 --> 00:43:53,829 the automotive world you use some sort of a gasket cement sealer or something 2332 00:43:53,829 --> 00:43:53,839 of a gasket cement sealer or something 2333 00:43:53,839 --> 00:43:55,510 of a gasket cement sealer or something of that nature on them 2334 00:43:55,510 --> 00:43:55,520 of that nature on them 2335 00:43:55,520 --> 00:43:56,550 of that nature on them to 2336 00:43:56,550 --> 00:43:56,560 to 2337 00:43:56,560 --> 00:43:58,390 to stick them in place 2338 00:43:58,390 --> 00:43:58,400 stick them in place 2339 00:43:58,400 --> 00:44:03,270 stick them in place while you're putting the joint together 2340 00:44:03,270 --> 00:44:03,280 2341 00:44:03,280 --> 00:44:04,870 and we have 2342 00:44:04,870 --> 00:44:04,880 and we have 2343 00:44:04,880 --> 00:44:07,430 and we have loading curves for the 2344 00:44:07,430 --> 00:44:07,440 loading curves for the 2345 00:44:07,440 --> 00:44:09,910 loading curves for the flat gaskets in the appendix which you 2346 00:44:09,910 --> 00:44:09,920 flat gaskets in the appendix which you 2347 00:44:09,920 --> 00:44:11,589 flat gaskets in the appendix which you get one of these days here in the near 2348 00:44:11,589 --> 00:44:11,599 get one of these days here in the near 2349 00:44:11,599 --> 00:44:13,670 get one of these days here in the near future 2350 00:44:13,670 --> 00:44:13,680 future 2351 00:44:13,680 --> 00:44:15,510 future and 2352 00:44:15,510 --> 00:44:15,520 and 2353 00:44:15,520 --> 00:44:16,550 and the 2354 00:44:16,550 --> 00:44:16,560 the 2355 00:44:16,560 --> 00:44:19,910 the flat gasket joint design 2356 00:44:19,910 --> 00:44:19,920 flat gasket joint design 2357 00:44:19,920 --> 00:44:21,750 flat gasket joint design bickford has quite a bit more coverage 2358 00:44:21,750 --> 00:44:21,760 bickford has quite a bit more coverage 2359 00:44:21,760 --> 00:44:23,349 bickford has quite a bit more coverage on it 2360 00:44:23,349 --> 00:44:23,359 on it 2361 00:44:23,359 --> 00:44:24,230 on it and 2362 00:44:24,230 --> 00:44:24,240 and 2363 00:44:24,240 --> 00:44:27,910 and so between that and the manufacturers 2364 00:44:27,910 --> 00:44:27,920 so between that and the manufacturers 2365 00:44:27,920 --> 00:44:29,430 so between that and the manufacturers chances are you can come up with enough 2366 00:44:29,430 --> 00:44:29,440 chances are you can come up with enough 2367 00:44:29,440 --> 00:44:31,750 chances are you can come up with enough information for that 2368 00:44:31,750 --> 00:44:31,760 information for that 2369 00:44:31,760 --> 00:44:36,230 information for that now gasket loads in flange joints 2370 00:44:36,230 --> 00:44:36,240 now gasket loads in flange joints 2371 00:44:36,240 --> 00:44:38,069 now gasket loads in flange joints leaks usually start at the point of 2372 00:44:38,069 --> 00:44:38,079 leaks usually start at the point of 2373 00:44:38,079 --> 00:44:41,030 leaks usually start at the point of maximum flange bending which is midway 2374 00:44:41,030 --> 00:44:41,040 maximum flange bending which is midway 2375 00:44:41,040 --> 00:44:43,109 maximum flange bending which is midway between adjacent uh bolts where the 2376 00:44:43,109 --> 00:44:43,119 between adjacent uh bolts where the 2377 00:44:43,119 --> 00:44:45,910 between adjacent uh bolts where the gasket's not compressed enough to seal 2378 00:44:45,910 --> 00:44:45,920 gasket's not compressed enough to seal 2379 00:44:45,920 --> 00:44:48,230 gasket's not compressed enough to seal uh a lot of you have run into that in 2380 00:44:48,230 --> 00:44:48,240 uh a lot of you have run into that in 2381 00:44:48,240 --> 00:44:50,550 uh a lot of you have run into that in the past with 2382 00:44:50,550 --> 00:44:50,560 the past with 2383 00:44:50,560 --> 00:44:52,390 the past with valve covers on cars 2384 00:44:52,390 --> 00:44:52,400 valve covers on cars 2385 00:44:52,400 --> 00:44:54,550 valve covers on cars they don't have enough 2386 00:44:54,550 --> 00:44:54,560 they don't have enough 2387 00:44:54,560 --> 00:44:56,069 they don't have enough fasteners in them and you have cork 2388 00:44:56,069 --> 00:44:56,079 fasteners in them and you have cork 2389 00:44:56,079 --> 00:44:58,550 fasteners in them and you have cork gaskets so you tighten them down and the 2390 00:44:58,550 --> 00:44:58,560 gaskets so you tighten them down and the 2391 00:44:58,560 --> 00:44:59,990 gaskets so you tighten them down and the thing will bow 2392 00:44:59,990 --> 00:45:00,000 thing will bow 2393 00:45:00,000 --> 00:45:02,470 thing will bow and leak in the middle and so you have 2394 00:45:02,470 --> 00:45:02,480 and leak in the middle and so you have 2395 00:45:02,480 --> 00:45:08,710 and leak in the middle and so you have you put cardboard under your car 2396 00:45:08,710 --> 00:45:08,720 2397 00:45:08,720 --> 00:45:11,589 and so to increase the load at the 2398 00:45:11,589 --> 00:45:11,599 and so to increase the load at the 2399 00:45:11,599 --> 00:45:13,430 and so to increase the load at the midway point you can look at three 2400 00:45:13,430 --> 00:45:13,440 midway point you can look at three 2401 00:45:13,440 --> 00:45:15,109 midway point you can look at three different ways of doing it one is to 2402 00:45:15,109 --> 00:45:15,119 different ways of doing it one is to 2403 00:45:15,119 --> 00:45:17,589 different ways of doing it one is to increase the number of bolts 2404 00:45:17,589 --> 00:45:17,599 increase the number of bolts 2405 00:45:17,599 --> 00:45:20,150 increase the number of bolts increase the flange thickness 2406 00:45:20,150 --> 00:45:20,160 increase the flange thickness 2407 00:45:20,160 --> 00:45:23,270 increase the flange thickness and increase the initial bolt torque 2408 00:45:23,270 --> 00:45:23,280 and increase the initial bolt torque 2409 00:45:23,280 --> 00:45:24,950 and increase the initial bolt torque so those are three things that you can 2410 00:45:24,950 --> 00:45:24,960 so those are three things that you can 2411 00:45:24,960 --> 00:45:26,550 so those are three things that you can look at all of which have their 2412 00:45:26,550 --> 00:45:26,560 look at all of which have their 2413 00:45:26,560 --> 00:45:29,430 look at all of which have their advantages and disadvantages 2414 00:45:29,430 --> 00:45:29,440 advantages and disadvantages 2415 00:45:29,440 --> 00:45:31,670 advantages and disadvantages the increased number of bolts 2416 00:45:31,670 --> 00:45:31,680 the increased number of bolts 2417 00:45:31,680 --> 00:45:33,510 the increased number of bolts since deflection is proportional to the 2418 00:45:33,510 --> 00:45:33,520 since deflection is proportional to the 2419 00:45:33,520 --> 00:45:36,230 since deflection is proportional to the cube of the span between bolt centers 2420 00:45:36,230 --> 00:45:36,240 cube of the span between bolt centers 2421 00:45:36,240 --> 00:45:38,150 cube of the span between bolt centers that cuts way down on the deflection of 2422 00:45:38,150 --> 00:45:38,160 that cuts way down on the deflection of 2423 00:45:38,160 --> 00:45:39,990 that cuts way down on the deflection of the flange 2424 00:45:39,990 --> 00:45:40,000 the flange 2425 00:45:40,000 --> 00:45:42,069 the flange and so uh 2426 00:45:42,069 --> 00:45:42,079 and so uh 2427 00:45:42,079 --> 00:45:46,230 and so uh so adding a bolted mid stand gives you 2428 00:45:46,230 --> 00:45:46,240 so adding a bolted mid stand gives you 2429 00:45:46,240 --> 00:45:49,510 so adding a bolted mid stand gives you gives you a 2430 00:45:49,510 --> 00:45:49,520 2431 00:45:49,520 --> 00:45:51,670 cut of 8 on the 2432 00:45:51,670 --> 00:45:51,680 cut of 8 on the 2433 00:45:51,680 --> 00:45:52,870 cut of 8 on the deflection 2434 00:45:52,870 --> 00:45:52,880 deflection 2435 00:45:52,880 --> 00:45:55,349 deflection and increases the gasket load the only 2436 00:45:55,349 --> 00:45:55,359 and increases the gasket load the only 2437 00:45:55,359 --> 00:45:57,190 and increases the gasket load the only thing is 2438 00:45:57,190 --> 00:45:57,200 thing is 2439 00:45:57,200 --> 00:45:59,349 thing is you increase the cost because you've now 2440 00:45:59,349 --> 00:45:59,359 you increase the cost because you've now 2441 00:45:59,359 --> 00:46:01,190 you increase the cost because you've now added another bolt 2442 00:46:01,190 --> 00:46:01,200 added another bolt 2443 00:46:01,200 --> 00:46:02,950 added another bolt another bull hole 2444 00:46:02,950 --> 00:46:02,960 another bull hole 2445 00:46:02,960 --> 00:46:05,589 another bull hole increasing the flange thickness 2446 00:46:05,589 --> 00:46:05,599 increasing the flange thickness 2447 00:46:05,599 --> 00:46:07,910 increasing the flange thickness now since flange deflection is inversely 2448 00:46:07,910 --> 00:46:07,920 now since flange deflection is inversely 2449 00:46:07,920 --> 00:46:09,510 now since flange deflection is inversely proportional the cube to the flange 2450 00:46:09,510 --> 00:46:09,520 proportional the cube to the flange 2451 00:46:09,520 --> 00:46:11,910 proportional the cube to the flange thickness you double the thickness it 2452 00:46:11,910 --> 00:46:11,920 thickness you double the thickness it 2453 00:46:11,920 --> 00:46:13,510 thickness you double the thickness it decreases the flange deflection by a 2454 00:46:13,510 --> 00:46:13,520 decreases the flange deflection by a 2455 00:46:13,520 --> 00:46:15,750 decreases the flange deflection by a factor of eight 2456 00:46:15,750 --> 00:46:15,760 factor of eight 2457 00:46:15,760 --> 00:46:16,950 factor of eight so 2458 00:46:16,950 --> 00:46:16,960 so 2459 00:46:16,960 --> 00:46:19,829 so that is a good thing except that 2460 00:46:19,829 --> 00:46:19,839 that is a good thing except that 2461 00:46:19,839 --> 00:46:22,550 that is a good thing except that you increase the weight and the cost of 2462 00:46:22,550 --> 00:46:22,560 you increase the weight and the cost of 2463 00:46:22,560 --> 00:46:24,630 you increase the weight and the cost of material so that's another thing that 2464 00:46:24,630 --> 00:46:24,640 material so that's another thing that 2465 00:46:24,640 --> 00:46:29,670 material so that's another thing that you have to weigh 2466 00:46:29,670 --> 00:46:29,680 2467 00:46:29,680 --> 00:46:32,309 now increasing the bolt torque 2468 00:46:32,309 --> 00:46:32,319 now increasing the bolt torque 2469 00:46:32,319 --> 00:46:33,670 now increasing the bolt torque is 2470 00:46:33,670 --> 00:46:33,680 is 2471 00:46:33,680 --> 00:46:36,470 is the cheapest way of doing it 2472 00:46:36,470 --> 00:46:36,480 the cheapest way of doing it 2473 00:46:36,480 --> 00:46:39,349 the cheapest way of doing it but if you increase it to a certain 2474 00:46:39,349 --> 00:46:39,359 but if you increase it to a certain 2475 00:46:39,359 --> 00:46:40,470 but if you increase it to a certain point 2476 00:46:40,470 --> 00:46:40,480 point 2477 00:46:40,480 --> 00:46:42,630 point the flange can bend 2478 00:46:42,630 --> 00:46:42,640 the flange can bend 2479 00:46:42,640 --> 00:46:43,750 the flange can bend in the middle 2480 00:46:43,750 --> 00:46:43,760 in the middle 2481 00:46:43,760 --> 00:46:45,430 in the middle because you're compressing it down under 2482 00:46:45,430 --> 00:46:45,440 because you're compressing it down under 2483 00:46:45,440 --> 00:46:47,270 because you're compressing it down under the bolt and allow it to bow up in the 2484 00:46:47,270 --> 00:46:47,280 the bolt and allow it to bow up in the 2485 00:46:47,280 --> 00:46:49,109 the bolt and allow it to bow up in the middle where to leak worse so 2486 00:46:49,109 --> 00:46:49,119 middle where to leak worse so 2487 00:46:49,119 --> 00:46:51,109 middle where to leak worse so particularly if you have a soft gasket 2488 00:46:51,109 --> 00:46:51,119 particularly if you have a soft gasket 2489 00:46:51,119 --> 00:46:53,510 particularly if you have a soft gasket like the kirk gaskets 2490 00:46:53,510 --> 00:46:53,520 like the kirk gaskets 2491 00:46:53,520 --> 00:46:55,030 like the kirk gaskets you you get leakage 2492 00:46:55,030 --> 00:46:55,040 you you get leakage 2493 00:46:55,040 --> 00:46:56,950 you you get leakage so and if the bolt is near the yield 2494 00:46:56,950 --> 00:46:56,960 so and if the bolt is near the yield 2495 00:46:56,960 --> 00:46:59,270 so and if the bolt is near the yield point a further increase in torque can't 2496 00:46:59,270 --> 00:46:59,280 point a further increase in torque can't 2497 00:46:59,280 --> 00:47:00,870 point a further increase in torque can't be made unless you use bolts with a 2498 00:47:00,870 --> 00:47:00,880 be made unless you use bolts with a 2499 00:47:00,880 --> 00:47:02,230 be made unless you use bolts with a higher strength 2500 00:47:02,230 --> 00:47:02,240 higher strength 2501 00:47:02,240 --> 00:47:04,230 higher strength so one of the el cheapo ways that you 2502 00:47:04,230 --> 00:47:04,240 so one of the el cheapo ways that you 2503 00:47:04,240 --> 00:47:06,230 so one of the el cheapo ways that you can do on this 2504 00:47:06,230 --> 00:47:06,240 can do on this 2505 00:47:06,240 --> 00:47:09,190 can do on this is put 2506 00:47:09,190 --> 00:47:09,200 2507 00:47:09,200 --> 00:47:12,069 extra diameter type uh washers under the 2508 00:47:12,069 --> 00:47:12,079 extra diameter type uh washers under the 2509 00:47:12,079 --> 00:47:13,670 extra diameter type uh washers under the bolts to spread the load out just a 2510 00:47:13,670 --> 00:47:13,680 bolts to spread the load out just a 2511 00:47:13,680 --> 00:47:15,589 bolts to spread the load out just a little bit sometimes that'll stop them 2512 00:47:15,589 --> 00:47:15,599 little bit sometimes that'll stop them 2513 00:47:15,599 --> 00:47:17,510 little bit sometimes that'll stop them from leaking but that's not something 2514 00:47:17,510 --> 00:47:17,520 from leaking but that's not something 2515 00:47:17,520 --> 00:47:21,750 from leaking but that's not something you'd want to put in an original design 2516 00:47:21,750 --> 00:47:21,760 2517 00:47:21,760 --> 00:47:22,829 now getting 2518 00:47:22,829 --> 00:47:22,839 now getting 2519 00:47:22,839 --> 00:47:26,069 now getting into bolted flanges for glass windows 2520 00:47:26,069 --> 00:47:26,079 into bolted flanges for glass windows 2521 00:47:26,079 --> 00:47:27,829 into bolted flanges for glass windows the reason i put this in is this is a 2522 00:47:27,829 --> 00:47:27,839 the reason i put this in is this is a 2523 00:47:27,839 --> 00:47:30,150 the reason i put this in is this is a special one and we've used it around 2524 00:47:30,150 --> 00:47:30,160 special one and we've used it around 2525 00:47:30,160 --> 00:47:31,990 special one and we've used it around here on 2526 00:47:31,990 --> 00:47:32,000 here on 2527 00:47:32,000 --> 00:47:34,630 here on designing of windows for 2528 00:47:34,630 --> 00:47:34,640 designing of windows for 2529 00:47:34,640 --> 00:47:36,390 designing of windows for pressure vessels because normally you 2530 00:47:36,390 --> 00:47:36,400 pressure vessels because normally you 2531 00:47:36,400 --> 00:47:38,870 pressure vessels because normally you don't think of a window as 2532 00:47:38,870 --> 00:47:38,880 don't think of a window as 2533 00:47:38,880 --> 00:47:39,829 don't think of a window as needing 2534 00:47:39,829 --> 00:47:39,839 needing 2535 00:47:39,839 --> 00:47:41,430 needing much in the way of gaskets and they more 2536 00:47:41,430 --> 00:47:41,440 much in the way of gaskets and they more 2537 00:47:41,440 --> 00:47:43,349 much in the way of gaskets and they more or less just slap them in 2538 00:47:43,349 --> 00:47:43,359 or less just slap them in 2539 00:47:43,359 --> 00:47:44,710 or less just slap them in and they're done with it they're in 2540 00:47:44,710 --> 00:47:44,720 and they're done with it they're in 2541 00:47:44,720 --> 00:47:46,710 and they're done with it they're in cameras and things of this nature but 2542 00:47:46,710 --> 00:47:46,720 cameras and things of this nature but 2543 00:47:46,720 --> 00:47:50,150 cameras and things of this nature but where you need to 2544 00:47:50,150 --> 00:47:50,160 2545 00:47:50,160 --> 00:47:51,430 use 2546 00:47:51,430 --> 00:47:51,440 use 2547 00:47:51,440 --> 00:47:52,950 use sight gauges 2548 00:47:52,950 --> 00:47:52,960 sight gauges 2549 00:47:52,960 --> 00:47:56,150 sight gauges or in our case actually you in cm1 use 2550 00:47:56,150 --> 00:47:56,160 or in our case actually you in cm1 use 2551 00:47:56,160 --> 00:47:58,470 or in our case actually you in cm1 use cameras through glass 2552 00:47:58,470 --> 00:47:58,480 cameras through glass 2553 00:47:58,480 --> 00:48:02,390 cameras through glass now you wind up with an optical quality 2554 00:48:02,390 --> 00:48:02,400 now you wind up with an optical quality 2555 00:48:02,400 --> 00:48:03,670 now you wind up with an optical quality window 2556 00:48:03,670 --> 00:48:03,680 window 2557 00:48:03,680 --> 00:48:04,950 window that costs 2558 00:48:04,950 --> 00:48:04,960 that costs 2559 00:48:04,960 --> 00:48:06,950 that costs several thousand dollars 2560 00:48:06,950 --> 00:48:06,960 several thousand dollars 2561 00:48:06,960 --> 00:48:09,349 several thousand dollars that you need to make sure that nothing 2562 00:48:09,349 --> 00:48:09,359 that you need to make sure that nothing 2563 00:48:09,359 --> 00:48:11,190 that you need to make sure that nothing happens to it 2564 00:48:11,190 --> 00:48:11,200 happens to it 2565 00:48:11,200 --> 00:48:13,109 happens to it so the way to make sure nothing happens 2566 00:48:13,109 --> 00:48:13,119 so the way to make sure nothing happens 2567 00:48:13,119 --> 00:48:15,589 so the way to make sure nothing happens to it is that you kind of pat it all the 2568 00:48:15,589 --> 00:48:15,599 to it is that you kind of pat it all the 2569 00:48:15,599 --> 00:48:17,670 to it is that you kind of pat it all the way around with rubber 2570 00:48:17,670 --> 00:48:17,680 way around with rubber 2571 00:48:17,680 --> 00:48:20,549 way around with rubber to keep it from touching the metal and 2572 00:48:20,549 --> 00:48:20,559 to keep it from touching the metal and 2573 00:48:20,559 --> 00:48:22,230 to keep it from touching the metal and then of course the 2574 00:48:22,230 --> 00:48:22,240 then of course the 2575 00:48:22,240 --> 00:48:24,390 then of course the one of the things about it in ours in 2576 00:48:24,390 --> 00:48:24,400 one of the things about it in ours in 2577 00:48:24,400 --> 00:48:26,790 one of the things about it in ours in particular was that the 2578 00:48:26,790 --> 00:48:26,800 particular was that the 2579 00:48:26,800 --> 00:48:29,670 particular was that the fastener design becomes a balancing act 2580 00:48:29,670 --> 00:48:29,680 fastener design becomes a balancing act 2581 00:48:29,680 --> 00:48:31,589 fastener design becomes a balancing act to seal it without overloading it 2582 00:48:31,589 --> 00:48:31,599 to seal it without overloading it 2583 00:48:31,599 --> 00:48:33,670 to seal it without overloading it because you don't want to overload it 2584 00:48:33,670 --> 00:48:33,680 because you don't want to overload it 2585 00:48:33,680 --> 00:48:36,710 because you don't want to overload it and the other thing too is glass is so 2586 00:48:36,710 --> 00:48:36,720 and the other thing too is glass is so 2587 00:48:36,720 --> 00:48:37,829 and the other thing too is glass is so brittle 2588 00:48:37,829 --> 00:48:37,839 brittle 2589 00:48:37,839 --> 00:48:39,430 brittle the thing that causes it to fail of 2590 00:48:39,430 --> 00:48:39,440 the thing that causes it to fail of 2591 00:48:39,440 --> 00:48:44,710 the thing that causes it to fail of course is surface imperfections and 2592 00:48:44,710 --> 00:48:44,720 2593 00:48:44,720 --> 00:48:46,230 you can't afford to scratch it with 2594 00:48:46,230 --> 00:48:46,240 you can't afford to scratch it with 2595 00:48:46,240 --> 00:48:47,990 you can't afford to scratch it with anything 2596 00:48:47,990 --> 00:48:48,000 anything 2597 00:48:48,000 --> 00:48:51,910 anything so uh it has a coefficient of thermal 2598 00:48:51,910 --> 00:48:51,920 so uh it has a coefficient of thermal 2599 00:48:51,920 --> 00:48:55,750 so uh it has a coefficient of thermal expansion about 1 6 that of metal so if 2600 00:48:55,750 --> 00:48:55,760 expansion about 1 6 that of metal so if 2601 00:48:55,760 --> 00:48:57,670 expansion about 1 6 that of metal so if you put it in and you have a temperature 2602 00:48:57,670 --> 00:48:57,680 you put it in and you have a temperature 2603 00:48:57,680 --> 00:48:58,710 you put it in and you have a temperature change 2604 00:48:58,710 --> 00:48:58,720 change 2605 00:48:58,720 --> 00:49:00,630 change now you have to put enough 2606 00:49:00,630 --> 00:49:00,640 now you have to put enough 2607 00:49:00,640 --> 00:49:03,510 now you have to put enough padding around it of some sort 2608 00:49:03,510 --> 00:49:03,520 padding around it of some sort 2609 00:49:03,520 --> 00:49:05,670 padding around it of some sort to allow it 2610 00:49:05,670 --> 00:49:05,680 to allow it 2611 00:49:05,680 --> 00:49:08,549 to allow it to be compressed 2612 00:49:08,549 --> 00:49:08,559 to be compressed 2613 00:49:08,559 --> 00:49:10,150 to be compressed uh by the 2614 00:49:10,150 --> 00:49:10,160 uh by the 2615 00:49:10,160 --> 00:49:12,470 uh by the material around it or expanded and so on 2616 00:49:12,470 --> 00:49:12,480 material around it or expanded and so on 2617 00:49:12,480 --> 00:49:14,549 material around it or expanded and so on without leaking so that's a balancing 2618 00:49:14,549 --> 00:49:14,559 without leaking so that's a balancing 2619 00:49:14,559 --> 00:49:15,430 without leaking so that's a balancing act 2620 00:49:15,430 --> 00:49:15,440 act 2621 00:49:15,440 --> 00:49:17,190 act so you sandwich it 2622 00:49:17,190 --> 00:49:17,200 so you sandwich it 2623 00:49:17,200 --> 00:49:19,190 so you sandwich it in flat rubber gaskets with a bumper 2624 00:49:19,190 --> 00:49:19,200 in flat rubber gaskets with a bumper 2625 00:49:19,200 --> 00:49:20,950 in flat rubber gaskets with a bumper strip around the outside of the window 2626 00:49:20,950 --> 00:49:20,960 strip around the outside of the window 2627 00:49:20,960 --> 00:49:22,630 strip around the outside of the window to keep it from direct contact with the 2628 00:49:22,630 --> 00:49:22,640 to keep it from direct contact with the 2629 00:49:22,640 --> 00:49:24,230 to keep it from direct contact with the metal 2630 00:49:24,230 --> 00:49:24,240 metal 2631 00:49:24,240 --> 00:49:25,430 metal and 2632 00:49:25,430 --> 00:49:25,440 and 2633 00:49:25,440 --> 00:49:27,190 and then 2634 00:49:27,190 --> 00:49:27,200 then 2635 00:49:27,200 --> 00:49:30,630 then the balancing act is to seal it so that 2636 00:49:30,630 --> 00:49:30,640 the balancing act is to seal it so that 2637 00:49:30,640 --> 00:49:32,069 the balancing act is to seal it so that it won't leak 2638 00:49:32,069 --> 00:49:32,079 it won't leak 2639 00:49:32,079 --> 00:49:33,910 it won't leak but yet not 2640 00:49:33,910 --> 00:49:33,920 but yet not 2641 00:49:33,920 --> 00:49:36,790 but yet not compress it too much 2642 00:49:36,790 --> 00:49:36,800 compress it too much 2643 00:49:36,800 --> 00:49:38,950 compress it too much so we have a typical 2644 00:49:38,950 --> 00:49:38,960 so we have a typical 2645 00:49:38,960 --> 00:49:40,549 so we have a typical design 2646 00:49:40,549 --> 00:49:40,559 design 2647 00:49:40,559 --> 00:49:42,870 design shown in figure 35 which you can go and 2648 00:49:42,870 --> 00:49:42,880 shown in figure 35 which you can go and 2649 00:49:42,880 --> 00:49:45,270 shown in figure 35 which you can go and put up there 2650 00:49:45,270 --> 00:49:45,280 put up there 2651 00:49:45,280 --> 00:49:47,829 put up there and 2652 00:49:47,829 --> 00:49:47,839 2653 00:49:47,839 --> 00:49:49,030 now 2654 00:49:49,030 --> 00:49:49,040 now 2655 00:49:49,040 --> 00:49:51,670 now this is a 2656 00:49:51,670 --> 00:49:51,680 this is a 2657 00:49:51,680 --> 00:49:55,670 this is a model of what we actually used in cm1 2658 00:49:55,670 --> 00:49:55,680 model of what we actually used in cm1 2659 00:49:55,680 --> 00:49:56,829 model of what we actually used in cm1 except 2660 00:49:56,829 --> 00:49:56,839 except 2661 00:49:56,839 --> 00:50:00,150 except that the one thing that i didn't show 2662 00:50:00,150 --> 00:50:00,160 that the one thing that i didn't show 2663 00:50:00,160 --> 00:50:02,230 that the one thing that i didn't show just for clarity was the o-ring that we 2664 00:50:02,230 --> 00:50:02,240 just for clarity was the o-ring that we 2665 00:50:02,240 --> 00:50:04,870 just for clarity was the o-ring that we had there but you see here i'll i'll use 2666 00:50:04,870 --> 00:50:04,880 had there but you see here i'll i'll use 2667 00:50:04,880 --> 00:50:06,950 had there but you see here i'll i'll use this one it's a little clearer 2668 00:50:06,950 --> 00:50:06,960 this one it's a little clearer 2669 00:50:06,960 --> 00:50:08,870 this one it's a little clearer here is the window 2670 00:50:08,870 --> 00:50:08,880 here is the window 2671 00:50:08,880 --> 00:50:10,470 here is the window you have a bumper strip around the 2672 00:50:10,470 --> 00:50:10,480 you have a bumper strip around the 2673 00:50:10,480 --> 00:50:12,150 you have a bumper strip around the outside now this is something that's not 2674 00:50:12,150 --> 00:50:12,160 outside now this is something that's not 2675 00:50:12,160 --> 00:50:13,910 outside now this is something that's not a sealer it's just to keep it when you 2676 00:50:13,910 --> 00:50:13,920 a sealer it's just to keep it when you 2677 00:50:13,920 --> 00:50:16,309 a sealer it's just to keep it when you drop it in the socket that it's in or 2678 00:50:16,309 --> 00:50:16,319 drop it in the socket that it's in or 2679 00:50:16,319 --> 00:50:18,710 drop it in the socket that it's in or the well there to keep from touching it 2680 00:50:18,710 --> 00:50:18,720 the well there to keep from touching it 2681 00:50:18,720 --> 00:50:20,870 the well there to keep from touching it you have rubber gaskets on the bottom 2682 00:50:20,870 --> 00:50:20,880 you have rubber gaskets on the bottom 2683 00:50:20,880 --> 00:50:23,109 you have rubber gaskets on the bottom you have a round gasket there 2684 00:50:23,109 --> 00:50:23,119 you have a round gasket there 2685 00:50:23,119 --> 00:50:25,750 you have a round gasket there and then you have one on top 2686 00:50:25,750 --> 00:50:25,760 and then you have one on top 2687 00:50:25,760 --> 00:50:28,390 and then you have one on top now what what you're doing here 2688 00:50:28,390 --> 00:50:28,400 now what what you're doing here 2689 00:50:28,400 --> 00:50:30,150 now what what you're doing here you're going metal to metal with this 2690 00:50:30,150 --> 00:50:30,160 you're going metal to metal with this 2691 00:50:30,160 --> 00:50:31,990 you're going metal to metal with this top flange 2692 00:50:31,990 --> 00:50:32,000 top flange 2693 00:50:32,000 --> 00:50:35,670 top flange now you have to use the tolerances of 2694 00:50:35,670 --> 00:50:35,680 now you have to use the tolerances of 2695 00:50:35,680 --> 00:50:36,710 now you have to use the tolerances of both 2696 00:50:36,710 --> 00:50:36,720 both 2697 00:50:36,720 --> 00:50:38,870 both on machining of this 2698 00:50:38,870 --> 00:50:38,880 on machining of this 2699 00:50:38,880 --> 00:50:41,670 on machining of this and machining of this surface in order 2700 00:50:41,670 --> 00:50:41,680 and machining of this surface in order 2701 00:50:41,680 --> 00:50:43,190 and machining of this surface in order to 2702 00:50:43,190 --> 00:50:43,200 to 2703 00:50:43,200 --> 00:50:46,309 to make sure that you can put that a window 2704 00:50:46,309 --> 00:50:46,319 make sure that you can put that a window 2705 00:50:46,319 --> 00:50:48,390 make sure that you can put that a window in there 2706 00:50:48,390 --> 00:50:48,400 in there 2707 00:50:48,400 --> 00:50:51,190 in there size your gaskets properly in some cases 2708 00:50:51,190 --> 00:50:51,200 size your gaskets properly in some cases 2709 00:50:51,200 --> 00:50:53,190 size your gaskets properly in some cases you have to grind them to get them to 2710 00:50:53,190 --> 00:50:53,200 you have to grind them to get them to 2711 00:50:53,200 --> 00:50:55,430 you have to grind them to get them to the right diameter i mean right 2712 00:50:55,430 --> 00:50:55,440 the right diameter i mean right 2713 00:50:55,440 --> 00:50:57,190 the right diameter i mean right thickness because the rubber is not 2714 00:50:57,190 --> 00:50:57,200 thickness because the rubber is not 2715 00:50:57,200 --> 00:50:58,790 thickness because the rubber is not close enough tolerance 2716 00:50:58,790 --> 00:50:58,800 close enough tolerance 2717 00:50:58,800 --> 00:51:01,750 close enough tolerance put it in there bolt it all down 2718 00:51:01,750 --> 00:51:01,760 put it in there bolt it all down 2719 00:51:01,760 --> 00:51:03,190 put it in there bolt it all down and seal it 2720 00:51:03,190 --> 00:51:03,200 and seal it 2721 00:51:03,200 --> 00:51:05,190 and seal it without hurting anything 2722 00:51:05,190 --> 00:51:05,200 without hurting anything 2723 00:51:05,200 --> 00:51:07,270 without hurting anything so that is a special design within 2724 00:51:07,270 --> 00:51:07,280 so that is a special design within 2725 00:51:07,280 --> 00:51:09,589 so that is a special design within itself and of course with your bolts you 2726 00:51:09,589 --> 00:51:09,599 itself and of course with your bolts you 2727 00:51:09,599 --> 00:51:10,950 itself and of course with your bolts you have to make sure that they're strong 2728 00:51:10,950 --> 00:51:10,960 have to make sure that they're strong 2729 00:51:10,960 --> 00:51:12,630 have to make sure that they're strong enough to 2730 00:51:12,630 --> 00:51:12,640 enough to 2731 00:51:12,640 --> 00:51:14,710 enough to go metal to metal and load the thing up 2732 00:51:14,710 --> 00:51:14,720 go metal to metal and load the thing up 2733 00:51:14,720 --> 00:51:19,270 go metal to metal and load the thing up without over stressing bolts 2734 00:51:19,270 --> 00:51:19,280 2735 00:51:19,280 --> 00:51:21,349 now the effect of friction in a clamp 2736 00:51:21,349 --> 00:51:21,359 now the effect of friction in a clamp 2737 00:51:21,359 --> 00:51:23,030 now the effect of friction in a clamp joint 2738 00:51:23,030 --> 00:51:23,040 joint 2739 00:51:23,040 --> 00:51:24,870 joint in most cases 2740 00:51:24,870 --> 00:51:24,880 in most cases 2741 00:51:24,880 --> 00:51:26,630 in most cases friction forces 2742 00:51:26,630 --> 00:51:26,640 friction forces 2743 00:51:26,640 --> 00:51:27,670 friction forces between 2744 00:51:27,670 --> 00:51:27,680 between 2745 00:51:27,680 --> 00:51:29,349 between clamp surfaces 2746 00:51:29,349 --> 00:51:29,359 clamp surfaces 2747 00:51:29,359 --> 00:51:31,430 clamp surfaces are not included in the shear 2748 00:51:31,430 --> 00:51:31,440 are not included in the shear 2749 00:51:31,440 --> 00:51:35,750 are not included in the shear calculations 2750 00:51:35,750 --> 00:51:35,760 2751 00:51:35,760 --> 00:51:37,670 the reason being 2752 00:51:37,670 --> 00:51:37,680 the reason being 2753 00:51:37,680 --> 00:51:39,190 the reason being that's too hard to determine what they 2754 00:51:39,190 --> 00:51:39,200 that's too hard to determine what they 2755 00:51:39,200 --> 00:51:40,549 that's too hard to determine what they are 2756 00:51:40,549 --> 00:51:40,559 are 2757 00:51:40,559 --> 00:51:42,549 are because if you've got 2758 00:51:42,549 --> 00:51:42,559 because if you've got 2759 00:51:42,559 --> 00:51:45,750 because if you've got oil or grease on the surfaces 2760 00:51:45,750 --> 00:51:45,760 oil or grease on the surfaces 2761 00:51:45,760 --> 00:51:47,750 oil or grease on the surfaces the your friction coefficient could be 2762 00:51:47,750 --> 00:51:47,760 the your friction coefficient could be 2763 00:51:47,760 --> 00:51:49,190 the your friction coefficient could be real low 2764 00:51:49,190 --> 00:51:49,200 real low 2765 00:51:49,200 --> 00:51:52,069 real low if you've got 2766 00:51:52,069 --> 00:51:52,079 2767 00:51:52,079 --> 00:51:53,990 striations of some kind on it it could 2768 00:51:53,990 --> 00:51:54,000 striations of some kind on it it could 2769 00:51:54,000 --> 00:51:55,910 striations of some kind on it it could get real high but you really don't know 2770 00:51:55,910 --> 00:51:55,920 get real high but you really don't know 2771 00:51:55,920 --> 00:51:57,430 get real high but you really don't know what it is 2772 00:51:57,430 --> 00:51:57,440 what it is 2773 00:51:57,440 --> 00:51:59,750 what it is so for that reason you normally 2774 00:51:59,750 --> 00:51:59,760 so for that reason you normally 2775 00:51:59,760 --> 00:52:01,190 so for that reason you normally don't include 2776 00:52:01,190 --> 00:52:01,200 don't include 2777 00:52:01,200 --> 00:52:02,470 don't include the 2778 00:52:02,470 --> 00:52:02,480 the 2779 00:52:02,480 --> 00:52:04,790 the axial force of the bolt times the 2780 00:52:04,790 --> 00:52:04,800 axial force of the bolt times the 2781 00:52:04,800 --> 00:52:06,790 axial force of the bolt times the coefficient of friction 2782 00:52:06,790 --> 00:52:06,800 coefficient of friction 2783 00:52:06,800 --> 00:52:07,829 coefficient of friction as a 2784 00:52:07,829 --> 00:52:07,839 as a 2785 00:52:07,839 --> 00:52:09,030 as a shear 2786 00:52:09,030 --> 00:52:09,040 shear 2787 00:52:09,040 --> 00:52:11,670 shear capability that you have now there are a 2788 00:52:11,670 --> 00:52:11,680 capability that you have now there are a 2789 00:52:11,680 --> 00:52:14,790 capability that you have now there are a few cases and the next page will show 2790 00:52:14,790 --> 00:52:14,800 few cases and the next page will show 2791 00:52:14,800 --> 00:52:16,630 few cases and the next page will show there are the actual friction forces 2792 00:52:16,630 --> 00:52:16,640 there are the actual friction forces 2793 00:52:16,640 --> 00:52:18,790 there are the actual friction forces that you can get 2794 00:52:18,790 --> 00:52:18,800 that you can get 2795 00:52:18,800 --> 00:52:22,630 that you can get you see you have a bolt preload of p 2796 00:52:22,630 --> 00:52:22,640 you see you have a bolt preload of p 2797 00:52:22,640 --> 00:52:24,710 you see you have a bolt preload of p and so you take that times the 2798 00:52:24,710 --> 00:52:24,720 and so you take that times the 2799 00:52:24,720 --> 00:52:26,470 and so you take that times the coefficient of friction on this surface 2800 00:52:26,470 --> 00:52:26,480 coefficient of friction on this surface 2801 00:52:26,480 --> 00:52:28,069 coefficient of friction on this surface and this surface and you got two forces 2802 00:52:28,069 --> 00:52:28,079 and this surface and you got two forces 2803 00:52:28,079 --> 00:52:29,589 and this surface and you got two forces here 2804 00:52:29,589 --> 00:52:29,599 here 2805 00:52:29,599 --> 00:52:30,390 here that 2806 00:52:30,390 --> 00:52:30,400 that 2807 00:52:30,400 --> 00:52:31,670 that two 2808 00:52:31,670 --> 00:52:31,680 two 2809 00:52:31,680 --> 00:52:33,829 two of these n forces and the n is the 2810 00:52:33,829 --> 00:52:33,839 of these n forces and the n is the 2811 00:52:33,839 --> 00:52:35,990 of these n forces and the n is the friction load 2812 00:52:35,990 --> 00:52:36,000 friction load 2813 00:52:36,000 --> 00:52:38,790 friction load uh which is the normal load 2814 00:52:38,790 --> 00:52:38,800 uh which is the normal load 2815 00:52:38,800 --> 00:52:40,549 uh which is the normal load times the coefficient of friction by 2816 00:52:40,549 --> 00:52:40,559 times the coefficient of friction by 2817 00:52:40,559 --> 00:52:41,670 times the coefficient of friction by definition 2818 00:52:41,670 --> 00:52:41,680 definition 2819 00:52:41,680 --> 00:52:42,390 definition so 2820 00:52:42,390 --> 00:52:42,400 so 2821 00:52:42,400 --> 00:52:45,109 so in some cases in the construction world 2822 00:52:45,109 --> 00:52:45,119 in some cases in the construction world 2823 00:52:45,119 --> 00:52:46,390 in some cases in the construction world they actually 2824 00:52:46,390 --> 00:52:46,400 they actually 2825 00:52:46,400 --> 00:52:47,589 they actually use 2826 00:52:47,589 --> 00:52:47,599 use 2827 00:52:47,599 --> 00:52:49,349 use this friction 2828 00:52:49,349 --> 00:52:49,359 this friction 2829 00:52:49,359 --> 00:52:51,589 this friction load 2830 00:52:51,589 --> 00:52:51,599 load 2831 00:52:51,599 --> 00:52:52,870 load when they 2832 00:52:52,870 --> 00:52:52,880 when they 2833 00:52:52,880 --> 00:52:55,510 when they are doing the joint calculations because 2834 00:52:55,510 --> 00:52:55,520 are doing the joint calculations because 2835 00:52:55,520 --> 00:52:56,950 are doing the joint calculations because they count on it 2836 00:52:56,950 --> 00:52:56,960 they count on it 2837 00:52:56,960 --> 00:52:58,790 they count on it but you it's not something that you 2838 00:52:58,790 --> 00:52:58,800 but you it's not something that you 2839 00:52:58,800 --> 00:53:01,349 but you it's not something that you would normally count on because it's too 2840 00:53:01,349 --> 00:53:01,359 would normally count on because it's too 2841 00:53:01,359 --> 00:53:03,829 would normally count on because it's too unpredictable 2842 00:53:03,829 --> 00:53:03,839 unpredictable 2843 00:53:03,839 --> 00:53:05,190 unpredictable now the 2844 00:53:05,190 --> 00:53:05,200 now the 2845 00:53:05,200 --> 00:53:06,870 now the compression 2846 00:53:06,870 --> 00:53:06,880 compression 2847 00:53:06,880 --> 00:53:09,750 compression cone of a bolted joint 2848 00:53:09,750 --> 00:53:09,760 cone of a bolted joint 2849 00:53:09,760 --> 00:53:13,030 cone of a bolted joint we covered this earlier there 2850 00:53:13,030 --> 00:53:13,040 we covered this earlier there 2851 00:53:13,040 --> 00:53:15,190 we covered this earlier there in the stiffness section 2852 00:53:15,190 --> 00:53:15,200 in the stiffness section 2853 00:53:15,200 --> 00:53:17,670 in the stiffness section but uh 2854 00:53:17,670 --> 00:53:17,680 but uh 2855 00:53:17,680 --> 00:53:20,870 but uh in the appendices we do give more stuff 2856 00:53:20,870 --> 00:53:20,880 in the appendices we do give more stuff 2857 00:53:20,880 --> 00:53:23,190 in the appendices we do give more stuff on it and the 2858 00:53:23,190 --> 00:53:23,200 on it and the 2859 00:53:23,200 --> 00:53:25,109 on it and the here's something that i alluded to 2860 00:53:25,109 --> 00:53:25,119 here's something that i alluded to 2861 00:53:25,119 --> 00:53:27,430 here's something that i alluded to earlier the bulk joint relative 2862 00:53:27,430 --> 00:53:27,440 earlier the bulk joint relative 2863 00:53:27,440 --> 00:53:29,990 earlier the bulk joint relative stiffness calculations 2864 00:53:29,990 --> 00:53:30,000 stiffness calculations 2865 00:53:30,000 --> 00:53:31,349 stiffness calculations and 2866 00:53:31,349 --> 00:53:31,359 and 2867 00:53:31,359 --> 00:53:34,630 and most of the ordinary designs are not a 2868 00:53:34,630 --> 00:53:34,640 most of the ordinary designs are not a 2869 00:53:34,640 --> 00:53:36,790 most of the ordinary designs are not a big requirement it's just that where you 2870 00:53:36,790 --> 00:53:36,800 big requirement it's just that where you 2871 00:53:36,800 --> 00:53:40,390 big requirement it's just that where you have say small areas 2872 00:53:40,390 --> 00:53:40,400 have say small areas 2873 00:53:40,400 --> 00:53:42,470 have say small areas that you would want to uh like for 2874 00:53:42,470 --> 00:53:42,480 that you would want to uh like for 2875 00:53:42,480 --> 00:53:45,430 that you would want to uh like for instance if you had some now if uh one 2876 00:53:45,430 --> 00:53:45,440 instance if you had some now if uh one 2877 00:53:45,440 --> 00:53:46,710 instance if you had some now if uh one of the things that would be a real 2878 00:53:46,710 --> 00:53:46,720 of the things that would be a real 2879 00:53:46,720 --> 00:53:49,030 of the things that would be a real problem if you have a bushing type thing 2880 00:53:49,030 --> 00:53:49,040 problem if you have a bushing type thing 2881 00:53:49,040 --> 00:53:50,790 problem if you have a bushing type thing around the bolt or a spacer or something 2882 00:53:50,790 --> 00:53:50,800 around the bolt or a spacer or something 2883 00:53:50,800 --> 00:53:52,870 around the bolt or a spacer or something like that then then you better go in and 2884 00:53:52,870 --> 00:53:52,880 like that then then you better go in and 2885 00:53:52,880 --> 00:53:54,710 like that then then you better go in and check happen real fast because you could 2886 00:53:54,710 --> 00:53:54,720 check happen real fast because you could 2887 00:53:54,720 --> 00:53:57,190 check happen real fast because you could get into trouble but if you have 2888 00:53:57,190 --> 00:53:57,200 get into trouble but if you have 2889 00:53:57,200 --> 00:53:58,549 get into trouble but if you have uh 2890 00:53:58,549 --> 00:53:58,559 uh 2891 00:53:58,559 --> 00:53:59,670 uh say 2892 00:53:59,670 --> 00:53:59,680 say 2893 00:53:59,680 --> 00:54:02,630 say uh steel and you're using steel bolts 2894 00:54:02,630 --> 00:54:02,640 uh steel and you're using steel bolts 2895 00:54:02,640 --> 00:54:04,309 uh steel and you're using steel bolts chances are the joint is going to be 2896 00:54:04,309 --> 00:54:04,319 chances are the joint is going to be 2897 00:54:04,319 --> 00:54:05,589 chances are the joint is going to be stiff enough that you don't have a 2898 00:54:05,589 --> 00:54:05,599 stiff enough that you don't have a 2899 00:54:05,599 --> 00:54:08,309 stiff enough that you don't have a problem with it you can look at it 2900 00:54:08,309 --> 00:54:08,319 problem with it you can look at it 2901 00:54:08,319 --> 00:54:10,549 problem with it you can look at it and take the the method at least work on 2902 00:54:10,549 --> 00:54:10,559 and take the the method at least work on 2903 00:54:10,559 --> 00:54:13,990 and take the the method at least work on it calculate a circular 2904 00:54:13,990 --> 00:54:14,000 it calculate a circular 2905 00:54:14,000 --> 00:54:16,309 it calculate a circular model for the stiffness if that is 2906 00:54:16,309 --> 00:54:16,319 model for the stiffness if that is 2907 00:54:16,319 --> 00:54:19,109 model for the stiffness if that is satisfactory then go no further now if 2908 00:54:19,109 --> 00:54:19,119 satisfactory then go no further now if 2909 00:54:19,119 --> 00:54:21,510 satisfactory then go no further now if if you were bowling say through 2910 00:54:21,510 --> 00:54:21,520 if you were bowling say through 2911 00:54:21,520 --> 00:54:22,630 if you were bowling say through all 2912 00:54:22,630 --> 00:54:22,640 all 2913 00:54:22,640 --> 00:54:25,990 all soft aluminum copper something like that 2914 00:54:25,990 --> 00:54:26,000 soft aluminum copper something like that 2915 00:54:26,000 --> 00:54:28,790 soft aluminum copper something like that then you would probably want to do some 2916 00:54:28,790 --> 00:54:28,800 then you would probably want to do some 2917 00:54:28,800 --> 00:54:30,710 then you would probably want to do some joint stiffness calculations to make 2918 00:54:30,710 --> 00:54:30,720 joint stiffness calculations to make 2919 00:54:30,720 --> 00:54:33,349 joint stiffness calculations to make sure that you're not in trouble 2920 00:54:33,349 --> 00:54:33,359 sure that you're not in trouble 2921 00:54:33,359 --> 00:54:36,390 sure that you're not in trouble but in in most cases you can get by with 2922 00:54:36,390 --> 00:54:36,400 but in in most cases you can get by with 2923 00:54:36,400 --> 00:54:38,549 but in in most cases you can get by with a minimal amount of joint stiffness 2924 00:54:38,549 --> 00:54:38,559 a minimal amount of joint stiffness 2925 00:54:38,559 --> 00:54:40,950 a minimal amount of joint stiffness calculations 2926 00:54:40,950 --> 00:54:40,960 calculations 2927 00:54:40,960 --> 00:54:44,789 calculations now bolding of dissimilar materials 2928 00:54:44,789 --> 00:54:44,799 now bolding of dissimilar materials 2929 00:54:44,799 --> 00:54:47,430 now bolding of dissimilar materials as i mentioned earlier in the centaur 2930 00:54:47,430 --> 00:54:47,440 as i mentioned earlier in the centaur 2931 00:54:47,440 --> 00:54:48,789 as i mentioned earlier in the centaur case where you went from room 2932 00:54:48,789 --> 00:54:48,799 case where you went from room 2933 00:54:48,799 --> 00:54:51,670 case where you went from room temperature to -300 or something like 2934 00:54:51,670 --> 00:54:51,680 temperature to -300 or something like 2935 00:54:51,680 --> 00:54:53,270 temperature to -300 or something like that 2936 00:54:53,270 --> 00:54:53,280 that 2937 00:54:53,280 --> 00:54:55,430 that with dissimilar materials there you got 2938 00:54:55,430 --> 00:54:55,440 with dissimilar materials there you got 2939 00:54:55,440 --> 00:54:57,190 with dissimilar materials there you got a real problem because of the 2940 00:54:57,190 --> 00:54:57,200 a real problem because of the 2941 00:54:57,200 --> 00:54:59,270 a real problem because of the differential thermal expansion and 2942 00:54:59,270 --> 00:54:59,280 differential thermal expansion and 2943 00:54:59,280 --> 00:55:00,710 differential thermal expansion and contraction 2944 00:55:00,710 --> 00:55:00,720 contraction 2945 00:55:00,720 --> 00:55:05,030 contraction of the materials because aluminum is 2946 00:55:05,030 --> 00:55:05,040 2947 00:55:05,040 --> 00:55:07,270 let's see something like 2948 00:55:07,270 --> 00:55:07,280 let's see something like 2949 00:55:07,280 --> 00:55:10,870 let's see something like three times i believe isn't it the uh 2950 00:55:10,870 --> 00:55:10,880 three times i believe isn't it the uh 2951 00:55:10,880 --> 00:55:12,950 three times i believe isn't it the uh on thermal 2952 00:55:12,950 --> 00:55:12,960 on thermal 2953 00:55:12,960 --> 00:55:15,349 on thermal something like three times as 2954 00:55:15,349 --> 00:55:15,359 something like three times as 2955 00:55:15,359 --> 00:55:20,710 something like three times as high a coefficient of steel is 2956 00:55:20,710 --> 00:55:20,720 2957 00:55:20,720 --> 00:55:23,430 and copper is way up there so if you're 2958 00:55:23,430 --> 00:55:23,440 and copper is way up there so if you're 2959 00:55:23,440 --> 00:55:25,190 and copper is way up there so if you're if you're bolding up a copper joint you 2960 00:55:25,190 --> 00:55:25,200 if you're bolding up a copper joint you 2961 00:55:25,200 --> 00:55:26,630 if you're bolding up a copper joint you have a temperature change you got to be 2962 00:55:26,630 --> 00:55:26,640 have a temperature change you got to be 2963 00:55:26,640 --> 00:55:28,630 have a temperature change you got to be real careful on it 2964 00:55:28,630 --> 00:55:28,640 real careful on it 2965 00:55:28,640 --> 00:55:30,309 real careful on it but uh 2966 00:55:30,309 --> 00:55:30,319 but uh 2967 00:55:30,319 --> 00:55:32,470 but uh then the the other thing 2968 00:55:32,470 --> 00:55:32,480 then the the other thing 2969 00:55:32,480 --> 00:55:34,150 then the the other thing that you needed watch for is the 2970 00:55:34,150 --> 00:55:34,160 that you needed watch for is the 2971 00:55:34,160 --> 00:55:36,150 that you needed watch for is the galvanic corrosion 2972 00:55:36,150 --> 00:55:36,160 galvanic corrosion 2973 00:55:36,160 --> 00:55:38,230 galvanic corrosion because unless the mating surfaces are 2974 00:55:38,230 --> 00:55:38,240 because unless the mating surfaces are 2975 00:55:38,240 --> 00:55:39,990 because unless the mating surfaces are insulated from each other 2976 00:55:39,990 --> 00:55:40,000 insulated from each other 2977 00:55:40,000 --> 00:55:42,230 insulated from each other and that was one of the reasons 2978 00:55:42,230 --> 00:55:42,240 and that was one of the reasons 2979 00:55:42,240 --> 00:55:43,510 and that was one of the reasons why the 2980 00:55:43,510 --> 00:55:43,520 why the 2981 00:55:43,520 --> 00:55:45,670 why the magnesium is kind of going out of vogue 2982 00:55:45,670 --> 00:55:45,680 magnesium is kind of going out of vogue 2983 00:55:45,680 --> 00:55:47,589 magnesium is kind of going out of vogue because how do you 2984 00:55:47,589 --> 00:55:47,599 because how do you 2985 00:55:47,599 --> 00:55:49,430 because how do you how do you 2986 00:55:49,430 --> 00:55:49,440 how do you 2987 00:55:49,440 --> 00:55:51,670 how do you insulate it satisfactorily that over a 2988 00:55:51,670 --> 00:55:51,680 insulate it satisfactorily that over a 2989 00:55:51,680 --> 00:55:53,510 insulate it satisfactorily that over a period of 20 years if it's used in the 2990 00:55:53,510 --> 00:55:53,520 period of 20 years if it's used in the 2991 00:55:53,520 --> 00:55:55,430 period of 20 years if it's used in the airplane component that it's going to 2992 00:55:55,430 --> 00:55:55,440 airplane component that it's going to 2993 00:55:55,440 --> 00:55:57,109 airplane component that it's going to stay insulated 2994 00:55:57,109 --> 00:55:57,119 stay insulated 2995 00:55:57,119 --> 00:55:59,030 stay insulated because a lot of these 2996 00:55:59,030 --> 00:55:59,040 because a lot of these 2997 00:55:59,040 --> 00:56:01,109 because a lot of these organic type things that they use for 2998 00:56:01,109 --> 00:56:01,119 organic type things that they use for 2999 00:56:01,119 --> 00:56:02,710 organic type things that they use for insulation 3000 00:56:02,710 --> 00:56:02,720 insulation 3001 00:56:02,720 --> 00:56:04,630 insulation the sealers that they put around rivets 3002 00:56:04,630 --> 00:56:04,640 the sealers that they put around rivets 3003 00:56:04,640 --> 00:56:06,870 the sealers that they put around rivets bolts and stuff like that on airplanes 3004 00:56:06,870 --> 00:56:06,880 bolts and stuff like that on airplanes 3005 00:56:06,880 --> 00:56:10,309 bolts and stuff like that on airplanes over a period of years can deteriorate 3006 00:56:10,309 --> 00:56:10,319 over a period of years can deteriorate 3007 00:56:10,319 --> 00:56:13,030 over a period of years can deteriorate and moisture and the other the other 3008 00:56:13,030 --> 00:56:13,040 and moisture and the other the other 3009 00:56:13,040 --> 00:56:14,950 and moisture and the other the other problem with the 3010 00:56:14,950 --> 00:56:14,960 problem with the 3011 00:56:14,960 --> 00:56:18,470 problem with the the fasteners on an airplane is that 3012 00:56:18,470 --> 00:56:18,480 the fasteners on an airplane is that 3013 00:56:18,480 --> 00:56:19,990 the fasteners on an airplane is that most of them 3014 00:56:19,990 --> 00:56:20,000 most of them 3015 00:56:20,000 --> 00:56:21,589 most of them you're looking at heads 3016 00:56:21,589 --> 00:56:21,599 you're looking at heads 3017 00:56:21,599 --> 00:56:24,069 you're looking at heads sticking out so if you have a crack that 3018 00:56:24,069 --> 00:56:24,079 sticking out so if you have a crack that 3019 00:56:24,079 --> 00:56:26,630 sticking out so if you have a crack that is starting at the edge of the hole 3020 00:56:26,630 --> 00:56:26,640 is starting at the edge of the hole 3021 00:56:26,640 --> 00:56:28,390 is starting at the edge of the hole it has to come out quite a ways before 3022 00:56:28,390 --> 00:56:28,400 it has to come out quite a ways before 3023 00:56:28,400 --> 00:56:33,030 it has to come out quite a ways before you can see it so so that has caused 3024 00:56:33,030 --> 00:56:33,040 you can see it so so that has caused 3025 00:56:33,040 --> 00:56:35,190 you can see it so so that has caused a lot of problems there 3026 00:56:35,190 --> 00:56:35,200 a lot of problems there 3027 00:56:35,200 --> 00:56:37,109 a lot of problems there the other thing that you need to look at 3028 00:56:37,109 --> 00:56:37,119 the other thing that you need to look at 3029 00:56:37,119 --> 00:56:39,190 the other thing that you need to look at is the yielding of softer materials 3030 00:56:39,190 --> 00:56:39,200 is the yielding of softer materials 3031 00:56:39,200 --> 00:56:42,789 is the yielding of softer materials because if you are say using a 3032 00:56:42,789 --> 00:56:42,799 because if you are say using a 3033 00:56:42,799 --> 00:56:45,349 because if you are say using a high-strength bolt in aluminum and you 3034 00:56:45,349 --> 00:56:45,359 high-strength bolt in aluminum and you 3035 00:56:45,359 --> 00:56:47,109 high-strength bolt in aluminum and you crank that up too much you can actually 3036 00:56:47,109 --> 00:56:47,119 crank that up too much you can actually 3037 00:56:47,119 --> 00:56:48,870 crank that up too much you can actually yield the aluminum in compression under 3038 00:56:48,870 --> 00:56:48,880 yield the aluminum in compression under 3039 00:56:48,880 --> 00:56:50,150 yield the aluminum in compression under the head 3040 00:56:50,150 --> 00:56:50,160 the head 3041 00:56:50,160 --> 00:56:52,950 the head without doing anything to the bolt 3042 00:56:52,950 --> 00:56:52,960 without doing anything to the bolt 3043 00:56:52,960 --> 00:56:54,549 without doing anything to the bolt so uh 3044 00:56:54,549 --> 00:56:54,559 so uh 3045 00:56:54,559 --> 00:56:56,069 so uh and then of course you've got to check 3046 00:56:56,069 --> 00:56:56,079 and then of course you've got to check 3047 00:56:56,079 --> 00:56:57,670 and then of course you've got to check the strengths at the temperature 3048 00:56:57,670 --> 00:56:57,680 the strengths at the temperature 3049 00:56:57,680 --> 00:57:00,150 the strengths at the temperature extremes because like for instance 3050 00:57:00,150 --> 00:57:00,160 extremes because like for instance 3051 00:57:00,160 --> 00:57:01,670 extremes because like for instance aluminum 3052 00:57:01,670 --> 00:57:01,680 aluminum 3053 00:57:01,680 --> 00:57:04,390 aluminum uh falls off drastically 3054 00:57:04,390 --> 00:57:04,400 uh falls off drastically 3055 00:57:04,400 --> 00:57:08,390 uh falls off drastically at only 250 degrees whereas steel most 3056 00:57:08,390 --> 00:57:08,400 at only 250 degrees whereas steel most 3057 00:57:08,400 --> 00:57:11,910 at only 250 degrees whereas steel most steels will go up to 700 and up before 3058 00:57:11,910 --> 00:57:11,920 steels will go up to 700 and up before 3059 00:57:11,920 --> 00:57:14,549 steels will go up to 700 and up before they start falling off in strength so so 3060 00:57:14,549 --> 00:57:14,559 they start falling off in strength so so 3061 00:57:14,559 --> 00:57:16,390 they start falling off in strength so so if you were 3062 00:57:16,390 --> 00:57:16,400 if you were 3063 00:57:16,400 --> 00:57:18,549 if you were tightening up an aluminum joint and you 3064 00:57:18,549 --> 00:57:18,559 tightening up an aluminum joint and you 3065 00:57:18,559 --> 00:57:21,750 tightening up an aluminum joint and you ran it up to say 250 300 degrees you 3066 00:57:21,750 --> 00:57:21,760 ran it up to say 250 300 degrees you 3067 00:57:21,760 --> 00:57:23,910 ran it up to say 250 300 degrees you could get yielding real easy under the 3068 00:57:23,910 --> 00:57:23,920 could get yielding real easy under the 3069 00:57:23,920 --> 00:57:28,630 could get yielding real easy under the heads of the bolts 3070 00:57:28,630 --> 00:57:28,640 3071 00:57:28,640 --> 00:57:31,510 now maximizing the effective length of 3072 00:57:31,510 --> 00:57:31,520 now maximizing the effective length of 3073 00:57:31,520 --> 00:57:33,349 now maximizing the effective length of fasteners of course when we discussed 3074 00:57:33,349 --> 00:57:33,359 fasteners of course when we discussed 3075 00:57:33,359 --> 00:57:35,430 fasteners of course when we discussed the stiffness ratios the effective 3076 00:57:35,430 --> 00:57:35,440 the stiffness ratios the effective 3077 00:57:35,440 --> 00:57:37,510 the stiffness ratios the effective length of the fastener was mentioned 3078 00:57:37,510 --> 00:57:37,520 length of the fastener was mentioned 3079 00:57:37,520 --> 00:57:38,870 length of the fastener was mentioned and this is important on the 3080 00:57:38,870 --> 00:57:38,880 and this is important on the 3081 00:57:38,880 --> 00:57:41,510 and this is important on the differential expansion contraction 3082 00:57:41,510 --> 00:57:41,520 differential expansion contraction 3083 00:57:41,520 --> 00:57:42,789 differential expansion contraction so 3084 00:57:42,789 --> 00:57:42,799 so 3085 00:57:42,799 --> 00:57:46,390 so it may be necessary to add a spring 3086 00:57:46,390 --> 00:57:46,400 it may be necessary to add a spring 3087 00:57:46,400 --> 00:57:48,470 it may be necessary to add a spring or a belleville washer under a bolt head 3088 00:57:48,470 --> 00:57:48,480 or a belleville washer under a bolt head 3089 00:57:48,480 --> 00:57:50,549 or a belleville washer under a bolt head to increase its effective length enough 3090 00:57:50,549 --> 00:57:50,559 to increase its effective length enough 3091 00:57:50,559 --> 00:57:52,390 to increase its effective length enough to satisfy the design so that it won't 3092 00:57:52,390 --> 00:57:52,400 to satisfy the design so that it won't 3093 00:57:52,400 --> 00:57:55,430 to satisfy the design so that it won't loosen up and 3094 00:57:55,430 --> 00:57:55,440 loosen up and 3095 00:57:55,440 --> 00:57:57,270 loosen up and the deflection of course is the pl over 3096 00:57:57,270 --> 00:57:57,280 the deflection of course is the pl over 3097 00:57:57,280 --> 00:57:59,349 the deflection of course is the pl over e so you increase l you're 3098 00:57:59,349 --> 00:57:59,359 e so you increase l you're 3099 00:57:59,359 --> 00:58:01,670 e so you increase l you're doing all right on it in fact on the 3100 00:58:01,670 --> 00:58:01,680 doing all right on it in fact on the 3101 00:58:01,680 --> 00:58:03,349 doing all right on it in fact on the exhaust system 3102 00:58:03,349 --> 00:58:03,359 exhaust system 3103 00:58:03,359 --> 00:58:04,549 exhaust system on uh 3104 00:58:04,549 --> 00:58:04,559 on uh 3105 00:58:04,559 --> 00:58:06,390 on uh some of the ford trucks 3106 00:58:06,390 --> 00:58:06,400 some of the ford trucks 3107 00:58:06,400 --> 00:58:10,710 some of the ford trucks they actually have a big spring 3108 00:58:10,710 --> 00:58:10,720 they actually have a big spring 3109 00:58:10,720 --> 00:58:13,270 they actually have a big spring on the bolt that holds the flange to the 3110 00:58:13,270 --> 00:58:13,280 on the bolt that holds the flange to the 3111 00:58:13,280 --> 00:58:15,030 on the bolt that holds the flange to the catalytic converter 3112 00:58:15,030 --> 00:58:15,040 catalytic converter 3113 00:58:15,040 --> 00:58:17,829 catalytic converter it's put on there i think to take the 3114 00:58:17,829 --> 00:58:17,839 it's put on there i think to take the 3115 00:58:17,839 --> 00:58:18,870 it's put on there i think to take the temperature 3116 00:58:18,870 --> 00:58:18,880 temperature 3117 00:58:18,880 --> 00:58:20,390 temperature differential that you get between the 3118 00:58:20,390 --> 00:58:20,400 differential that you get between the 3119 00:58:20,400 --> 00:58:21,510 differential that you get between the materials 3120 00:58:21,510 --> 00:58:21,520 materials 3121 00:58:21,520 --> 00:58:23,670 materials on because you can go from room 3122 00:58:23,670 --> 00:58:23,680 on because you can go from room 3123 00:58:23,680 --> 00:58:26,390 on because you can go from room temperature up to about 3124 00:58:26,390 --> 00:58:26,400 temperature up to about 3125 00:58:26,400 --> 00:58:28,390 temperature up to about 1300 degrees or something like that on 3126 00:58:28,390 --> 00:58:28,400 1300 degrees or something like that on 3127 00:58:28,400 --> 00:58:32,789 1300 degrees or something like that on them 3128 00:58:32,789 --> 00:58:32,799 3129 00:58:32,799 --> 00:58:36,630 okay we'll take a break cure for now and 3130 00:58:36,630 --> 00:58:36,640 okay we'll take a break cure for now and 3131 00:58:36,640 --> 00:58:38,710 okay we'll take a break cure for now and come back up with the match drilling of 3132 00:58:38,710 --> 00:58:38,720 come back up with the match drilling of 3133 00:58:38,720 --> 00:58:41,030 come back up with the match drilling of fastener holes 3134 00:58:41,030 --> 00:58:41,040 fastener holes 3135 00:58:41,040 --> 00:58:45,240 fastener holes which is an important one