Semi Phenomenological Modelling of the Behaviour of Trip Steels- Application to Sheet Metal Forming

A semi-phenomenological model is developed based on a mean-field description of the TRIP behaviour for the simulation of metal forming processes [1]. Within the metastable austenitic phase exhibiting martensitic transformation, a mean field approach is introduced at the phase level with the concept of Mean Instantaneous Transformation Strain (MITS) accompanying transformation. Within the framework of the thermodynamics of irreversible processes, a transformation criterion and martensitic volume fraction evolution are determined. A multiscale scheme is used to model the behaviour of TRIP steels. The model reproduces the increase in ductility and the multiaxial behaviour of a multiphased TRIP steel. In this study, this new model is implemented in the finite element code Abaqus Explicit for metal forming simulations. The simulations are compared to experimental data.