Physically-motivated elasto-visco-plastic model for the large strain-rate behavior of steels

Abstract

A physically based elasto-visco-plastic constitutive model is presented and compared to experimental results for a DD14 mild steel. The model requires significantly fewer material parameters compared to other visco-plasticity models from the literature while exhibiting very good accuracy. Accordingly, the parameter identification is simple and intuitive, requiring a relatively small set of experiments. The strain-rate sensitivity modeling is not restricted to a particular hardening law and thus provides a general framework in which advanced hardening equations can be adopted and compared. The model has been implemented in the commercial finite element code Abaqus/Explicit. First predictions compared to experiments are analyzed and underline the effect of hardening law and strain-rate sensitivity on 3D finite element simulations. The model has been also applied as the basis for a homogenization approach at the phase scale; preliminary investigations showed the benefits of coupling such an approach with scale-transition technique where microstructure-relevant data can explicitly enter the model and may be used for material design simulations.