A crystal plasticity finite element-based approach to model the constitutive behavior of multi-phase steels

Abstract

Steels are the most commonly used multi-phase materials in the industry, and their mechanical behaviors depend on the microstructure, composition, and phase fractions. Generally, the material behaviors need to be measured by experiments like a tensile test or split Hopkinson bar test, which is very time-consuming and expensive. Once the heat treatment and phase fractions are changed, it needs to be tested again, and, to avoid this, a better method is required to obtain the material behavior quickly and easily. In this study, a novel multi-scale approach is described to predict the material behaviors of multi-phase steels based on the phase fractions. A crystal plasticity finite element method is used to obtain the material behavior of each phase at a micro-scale with elevated strain rates, which is validated with experimental data or theoretical models at static or quasi-static conditions. Then a homogenization procedure with the rule of mixture method, which is based on the phase fractions measured from the microstructure characterization, is used to get the macro-scale constitutive behavior, and it is then implemented into the commercial software Abaqus/Standard to simulate the process of tensile test and compared with the experimental data. Good agreements are obtained between simulation and experimental results.