PHENOMENOLOGICAL MODELING OF STRAIN HARDENING, PHASE TRANSFORMATION AND DAMAGE EFFECTS OF TRIP-STEELS

In this study, the constitutive modeling of loading state dependent strain hardening and martensite evolution of high alloyed TRIP-steels are addressed, which are experimentally observed comparing uni-axial tension and compression test results. Furthermore, a damage mechanics extension of the model is proposed, which is based on the continuum damage mechanics framework. An implicit gradient based enrichment method is applied to realize a non-local damage formulation. For the implementation into the commercial FEM-software ABAQUS, the analogy between the additional Helmholtz type equation of implicit gradient enrichment and the already built-in heat conduction equation is used. Finally, the developed model is fitted to experimental data and cell model calculations. A convergence study using the non-local extension is discussed.