A multi-scale modelling of 3rd generation advanced high strength steels to account for anisotropic evolution of yield surface and plastic potential

Abstract

Multi-scale models were integrated to account for anisotropic mechanical behaviour of the 3rd generation advanced high strength steels (3GAHSS). The micromechanical response of individual phases of the 3GAHSS in non-proportional loading was characterized based on the atomistically informed dislocation dynamics (DD) simulations. The characterized mechanical properties were utilized for the development of the crystal plasticity model to properly account for the cross-loading effect on the interactions of the dislocations. To predict anisotropic evolution of yield surface and plastic potential in non-proportional loading of the 3GAHSS, 3D representative volume elements (3D RVEs) were developed based on the microstructural information from the EBSD data. As for the practical applications such as predictions of formability and spring-back, an advanced phenomenological model was also developed based on a combined type nonlinear isotropic-kinematic hardening law and two-yield surface plasticity.