Nonlinear material

[Stress Solver]

Does anyone know the governing equation used when specifying a nonlinear material in the stress solver? They ask for initial yield stress and hardening parameter, but I want to know exactly how they are using these values...

[Shobha]

The only nonlinear material model supported by this program is an elastic hardening plastic model.

I don't know of any future plans to allow subroutines to specify others.