Von Mises Stresses

[stav1987]

I have just carried out some analyses on thin plates under a centred point load on both elastic shell 63 and plastic shell 43. The output from ANSYS showed that the VMS for elastic 63 > VMS plastic all other variables remaining unchanged.
Does anyone know how to justify this?

Thanks for any help Stavros

 

[TERIO]

What material properties did you use?

 

[stav1987]

I used a young's modulus of 210e9 and a von mises of 0.3
however, I have only used the linear elastic isotropic material model
I noticed yesterday that I have not included a non-linear model! I understand the tangent modulus is the gradient of the stress strain curve but where can I find a value for this?