Plastic strain

Axel_A

Dear Altair team,

For shell analysis, after plasticization, do I need to use "Equivalent plastic strain - EPS" or "VM plastic strain"? It looks like these 2 values are not the same.

What is the best value to consider to have a valid level of plasticization?

Green: Element strain

Blue: VM plastic strain

In this example, how can the EPS be higher (x3) than element strain?

Best,

Axel

Alberto Campagna

Hi Axel,

equivalent plastic strain, and VM plastic strain are not computed in the same way. You can find details in this discussion:

https://community.altair.com/discussion/38329/equivalent-plastic-strain-vs-tensor-plastic-strain

The 3x difference in your graph indeed seems a little bit too high. Can you request strain at gauss points and re-evaluate? Also check shell formulation you are using.

Kind Regards

Alberto