Bending stress in horizontal pressure vessel saddle base plate
Bending stress in horizontal pressure vessel saddle base plate
(OP)
I am looking for a correct formula for the bending stress in the saddle base plate of a horizontal pressure vessel. The current formula I have has incorrect units.
fb = [(6*M)/(tb^2)] is the formula I'm using (units of lb/in instead is lb/in^2), where fb = bending stress, M = bending moment, tb = base plate thickness.
I have limited access to references so I would appreciate any formula or online reference site anyone could provide.
Also, if this is the correct formula could someone explain to me why the units are not in psi.
fb = [(6*M)/(tb^2)] is the formula I'm using (units of lb/in instead is lb/in^2), where fb = bending stress, M = bending moment, tb = base plate thickness.
I have limited access to references so I would appreciate any formula or online reference site anyone could provide.
Also, if this is the correct formula could someone explain to me why the units are not in psi.





RE: Bending stress in horizontal pressure vessel saddle base plate
I think you're on the right track and the formula that you are using is for a unit length of base plate. The formula for the section modulus is S = b*t^2 / 6, and the bending stress is M/S Substituting you get M/S = 6*M / b*(t^2)
Then if you are looking at a unit length of the base plate, b=1, you reduce to your formula 6*M/t^2 (which actually is units of psi if you leave the b=1" term in the denominator.
RE: Bending stress in horizontal pressure vessel saddle base plate
RE: Bending stress in horizontal pressure vessel saddle base plate
This may not be your case, but recently I was involved in a repair to the foundations of a rather large (thermal) vessel that was destroying its foundation.