I’m working on a shell bridge made out of concrete. The goal is to optimize the thickness of the shell. For this I need my principal stresses of the shell. There are four loadcases so at first I used the shell view four times to see what the principal stresses are. This caused lots of time to make so therefore I tried to use the ShellVecResults. However these sigma1 and sigma 2 values differ from the ones out of the shell view component.
Is there somebody who can explain this difference?
I attached a picture to show the difference.