Non Linear Material Analysis Question

[thecadguy]

Dear All,

I am running a fairly simple non -linear material analysis of a plastic clip in UGNX sol 601. The stress strain curve has a slight negative slope in the plastic region and I have noticed that the solver seems to stop at the peak of the curve just before it starts down in the negative slope. This is at around 22 Mpa and 5% strain. The curve goes out to 20 Mpa at 20% strain. I am most interested in spring back and wanted to know if I am missing something to get the solver to follow all the was to the 20% region. I am using the large strain/displacement options?

Any help or comments would be appreciated?

Thanks,

THECADGUY

 

[rothers]

You can't have a negative going stress-stain curve. Looks like you've used engineering rather then true stress-strain values.