Finite element simulation of shape memory alloy wires using a user material subroutine: Parametric study on heating rate, conductivity, and heat convection

In this work, the thermal and mechanical responses of shape memory alloys are studied under different loading and boundary conditions. To this end, a common one-dimensional constitutive model for shape memory alloys capturing both pseudoelasticity and shape memory effect is implemented into ABAQUS commercial finite element package via a user material subroutine. The main benefit of this one-dimensional user material is its capability to simulate any mechanical as well as thermal loading path. Hence, it can be utilized in finite element simulation of any complicated smart structure consisting of shape memory alloy wires. To validate the proposed numerical approach, its predictions are shown to be in a good agreement with those obtained by analytical and other approved numerical solutions under different thermal and mechanical loading and boundary conditions. Since shape memory alloys are integrated into many applications as actuation elements, the actuation response of an axial shape memory alloy actuator heated from one end is studied using finite element method. Finally, the developed user material is employed in finite element simulation of a smart landing gear as a real-world smart structure.