MODELING OF THE MECHANICAL EFFECTS OF PHA SE-TRANSFORMATIONS FOR STRUCTURAL COMPUTATIONS

A set of constitutive equations are proposed to take into account the predominant mechanical effects due to solid state phase transformation s in steels under multi-axial loading. The aim of this work is to form alize, for structural computations (heat treatment and welding), the m ain experimental and theoretical results available in the literature. The internal stresses generated by the transformation induced flow are represented by internal variables in the framework of the thermodynam ics of the irreversible processes. We propose a mathematical formulati on of the strain-hardening effects on the transformation induced plast ic flow and of the transformation induced hardening on the ''classical '' plasticity. The constitutive equations have been implemented into t he F.E. code ZeBuLoN and we briefly present a thermo-metallurgical and mechanical simulation with hardening couplings.