An integrated computational materials engineering approach for constitutive modelling of 3rd generation advanced high strength steels

Abstract

Constitutive models for the 3rd generation advanced high strength steels (3GAHSS) were developed based on integrated computational materials engineering (ICME) approach. Multiple scale models from the atomic level to the continuum level were integrated to generate material models that can be used to accurately model the material response of the 3GAHSS depending on their microstructures. In addition to the shear deformation in the slip systems, martensitic phase transformation induced by the plastic deformation of the retained austenite was accounted for in the crystal plasticity model. Atomistic simulation results based on the density functional theory (DFT) calculations were utilized to obtain the lattice parameters and elastic coefficients, while micropillar compression data and in-situ HEXRD test data were utilized for the characterization of the developed crystal plasticity model. 3D representative volume elements (RVE) were generated to represent the mechanical behaviour of the 3GAHSS by considering the distributions of grain size, grain shape, and grain orientation measured from the EBSD data. To predict macroscopic mechanical behaviour of 3GAHSS in complex deformations, finite element simulations were performed based on the developed crystal plasticity model and generated 3D RVEs. The CPFE simulation results were implemented in the advanced phenomenological models and utilized to accurately predict the formability and spring-back of 3GAHSS.