Principal Stresses in Shells (S4R) - Section Points

[g.alshamsi]

Hello all,

I'm trying to determine the angle of inclination of a steel panel. The panel is a thin steel sheet made up of S4R elements (explicit solver) subjected to a lateral force. First I need to determine which elements exceed the yield stress(fy) then I need to extract the stress components to calculate the angle. My question is which section point is the most accurate representation of the stresses (principal and components)? The manual states that the stress contour in the odb file are always drawn w.r.t section point 1 which I understand is the one at the bottom. I'm using 9 integration points for the shell thickness with Simpson's rule. The results for the 1st, 5th, and 9th point are quite different. My intuition says the 5th point (middle for my case) should be a reasonable estimate of the actual stress distribution however I can't find anything to support my claim.

Any advice is greatly appreciated.

Cheers,

 

[FEA way]

Usually, the best way is to set Envelope in Result —> Section Points so that the contour plot shows maximum value from all section points in each element.

 

[g.alshamsi]

Thanks man,

Cheers