A new multi-scale framework to incorporate microstructure evolution in phenomenological plasticity: Theory, explicit finite element formulation, implementation and validation

Representation of anisotropy is a key factor in the predictive capabilities of finite element simulations of metal alloys. Micromechanics-based computational models, such as crystal plasticity, have served as a powerful tool over phenomenological-based models for their ability to predict initial and evolution of anisotropy. However, these micromechanics-based models are often sacrificed for much faster phenomenological models that do not capture microstructure evolution. In this paper, a new multi-scale framework is presented to incorporate microstructure evolution into phenomenological plasticity. Crystal plasticity is used to calibrate yield functions and microstructural evolution in a phenomenological manner using only a uniaxial tensile response and an electron backscatter diffraction (EBSD) map. Both single crystal and polycrystal mechanical properties are calibrated and predicted by the new framework. The constitutive framework is implemented into the commercial finite element software, LS-DYNA, to simulate the large strain behaviour of the extruded aluminum alloy (AA) 6063-T6. The simulations, which are compared to corresponding experiments, highlight the importance of capturing microstructural evolution in the simulation of large deformation in lab-scale components.