Hello,
I am trying to find the stress on a pin caused by a reaction force. The pin holds a jaw arm for a gear/bearing puller. I've attached pictures of what the Jaw arm + pin would look like, and also just the pin itself with fixtures and a load applied. Before I ran the simulation I did a simple shear calculation on the pin:
shear = V/A = 4V/pi*d^2
'V' in this case is going to be a load of 10/3 Tons, so about 6667 lbf. The diameter of the pin is 0.375 in. The shear stress is about 60,000 psi using that calculation.
So I set up the pin as shown, figuring the jaw arm only contacts a portion of that surface causing the reaction. Once I get done with the simulation I get a max shear stress of over 100,000 psi as shown. Am I missing something here? Maybe I oversimplified my hand calculation, I'm not sure...
Hi Adam:
The hand calculation looks correct but I recall that it represents the average shear stress over the entire pin cross section. You might try plotting the TXY or TXZ (or whichever shear component is appropriate). Nevertheless the stress exactly at the boundary between the fixture and the load would be very high because of the singularity (the super-rigidity of the fixture right at the boundary). You might try a contact analysis with a bearing holding the pin (as opposed to fixing the pin ends), which would help mitigate the stresses due to the elasticity of the bearing. Still, I believe the stress at the contact junction would be very high, but perhaps not that high. Hope this helps a little. -Tony