Hi Raphaël,
to my knowledge, you can't describe such a behaviour using build-in Aster behaviours.
In plasticity, one way to do it would have been to use two yield surfaces able to describe yield differential effects (such as Cazacu 2004), one for the behaviour and tension and one for the behaviour in compression, and appropriatly choose the two isotropic hardening laws. This is already hard work.
In elasticity, it would try to express a convex elastic potential as a function of:
- the positive and negative parts of the elastic strain
- the positive and negative value of the trace of the elastic strain
and then try to derive the appropriate conditions to retrieve an abitrary stress strain curve. I don't know if this has already been done nor if it is tractable (and convexity surely imposes some restrictions to the stress-strain curve)
If you manage to do this, contact me as your best options would probably to implement it with MFront.
Best regards,
Thomas
