Crystal plasticity modelling framework for fully implicit time integration of coupled phase transformation and slip in shape memory alloys

A crystal-plasticity based rate-dependent framework is developed for capturing the coupled phase transformation-slip deformation modes at the crystal-scale in NiTi shape memory alloy using a fully-implicit time integration scheme. The computational procedures developed in this work have been successfully incorporated as a user material subroutine (UMAT) in the commercial finite element code (ABAQUS Standard). The current modelling framework demonstrates the ability to use either Habit plane variants (HPVs) and Lattice correspondence variants (LCVs) for modelling phase transformation. The predictions from the simulations are compared against previously published experimental data in literature for single and polycrystalline representative volume element (RVE) at various temperatures. The effect of temperature and texture on phase transformation and residual strain is investigated systematically. The computational benefits of the current numerical implementation of the model is demonstrated and compared against previously reported models.