Rivet & Bolt Connection

[patioshep]

Merm 51-10 says that the cross sectional area to resist tension in the lap plate is At = t (b-Nd) , where t = thickness of the plate. However, in 6 min solution MD # 68 & 71 has the equation At = 2t (b-Nd). Is there a real difference between the two equations or perhaps a misprint?

thanks

 

[Capt Worley PE]

Make sure t means the same thing in both equations. Looks like it means distance from centerline to outer edge in 6MS (IOW, half thickness), but I don't have a way to verify that since I don't have the book.

 

[Matt-NM]

I remember this to be confusing as well. There was errata posted for problem #68 of the six-minute solutions. A=2t(b-Nd) was changed to A = t(b-Nd) which changed the total area to 1.313 in^2, and thus the final answer was 19,047 lbf/in^2. Problem #71 in the six minute solutions multiplies by 2 because there are two fasteners in line with each other as opposed to 51-10 of MERM where there is only one.

Hope this helps. I remember this throwing me for a small loop when I studied it also.

 

[patioshep]

ok.. that makes sense now. Glad to see MD people are out there.

More questions to come....

thanks guys