How can I get the stress-strain curve after performing a shock compression

Dear all,

I’m using fix msst to simulate a uniaxial compression. I need the tensile stress-strain curve of the sample after the compression, so after writing a restart, I tried to perform a simple tension on the sample. but since the boundary in “z” direction must be “p” for fix msst and “s” for tension, I can’t get the right amounts for stress and strain. So what should I do?

Thanks a lot,