Three Dimensional Crystal Plasticity Finite Element Simulation of Notched Tensile Samples of Pseudoelastic NiTi Shape Memory Alloys

摘要

We present a crystal plasticity finite element (CPFE) model for pseudoelastic NiTi shape memory alloy (SMA). Simulations of uniaxial tensile deformation of notched single crystal specimens of NiTi SMA at isothermal condition have been carried out. Predicted martensitic transformation is compared qualitatively against the one reported in literature. Constitutive model has been implemented within a user material subroutine VUMAT in ABAQUS/Explicit. Two different crystallographic orientation samples with tensile axes along the [100] and [111] are studied. Martensitic transformation in the surrounding region of crack tip in notched samples are determined in simulation and the results are compared with the existing experimental data from literature. For [100] notch sample, martensitic transformation starts above and below the notch tip and for [1 1 1] sample, the transformation starts ahead of notch tip. The simulation results show orientation dependence of martensitic transformation and are qualitatively in good agreement with the experimental results.