Learning Forum

[Peter Yip]

Hi Forum,

I have used the Mie-Gruneisen equation of state for water and am trying to verify that the response I am getting is correct. Since the water is being fully defined by the EOS (i.e. strength model = NULL), the response should be pretty easy to plot since it would just be a P-V (or in this case P-mu) curve. I have found that the internal energy per unit volume, E, is really important because all the other terms become quite small. However, the LS-DYNA manual doesn't go over how this is computed that well... How should I handle that?

Thanks,

Peter

[Ushnish Basu]

The first history variable after the plastic strain slot holds the internal energy if an EOS is used. (set NEIPH in DATABASE_EXTENT_BINARY or OPTION1 in DATABASE_ELOUT to get history variables output)

The calculation of internal energy is described at the end of Appendix B in the Keyword Manual, in the section "Implementation Discussion"

 

[Peter Yip]

Ushnish,

Thank you for your response. I will pull the internal energy and develop my P-V (or P-mu) curve to see if it matches.

Peter