Stress output in Karamba

Hi

I'm busy with optimizing a folded plate structure (see picture). To do this I need to limit the maximum stress so it doesn't exceed the material limit. I can visualise different stress types with the ShellView-component (picture attached), but that doesn't give me a numeric output. With the ShelVecResults-compontent (picture attached) I can get an output for the first and second principal stress, but I don't realy know how this applies to a mesh. It seems that the values I get from this component also doesn't match with the results visualized in the ShellView-component. What's the difference between the two? I think it's best to use the 'Van Mises Stress', because it gives a value for the stress in all directions, but I can't find a way to get a numeric output for this. So is there someone that can help me to get numeric values for the stresses in my plates?

Kind regards

Reinout