Hi, 

I am analysing a composite as shown in the figure with four distinct phases. All the phases has cam-clay model as the constitutive behaviour. Each phase has separate parameters for cam-clay model so that the yield function is different from phase to phase. 

1) Is it possible to obtain softening after the peak in cam clay model. When I give the softening in the tabular format, I get an error saying compression yield should be increasing (i.e - hardening)

2) Since there are four phases and I am not specifying hardening, each phase will enter in to perfect plasticity after each phase passes its yield point. Hence, when I load this composite in compression, the stress strain curve I get is a superposition of each phase. Is there any way I can make the stresses in a phase zero after the stress in that phase is past is yield point ? 

Thanks