Numerical Simulation of Expansion Deformation of the TiNiFe Shape Memory Alloy Ring

The excellent recovery performance of TiNiFe shape memory alloy is closely related to the predeformation in the martensitic state. Based on the classical phenomenological constitutive model, the constitutive relationship suitable for the mechanical properties of TiNiFe alloy is constructed by introducing plastic strain. Aiming at the problems of uneven size and difficulty in characterizing stress and strain state in the deformation of ring parts after expansion deformation, the finite element simulation model of cryogenic temperature expansion deformation of shape memory alloy is established by using the UMAT interface of Abaqus. The effects of die angle and ring wall thickness on the stress state and geometric size of the TiNiFe alloy ring expansion process are investigated. The results show that for the same wall thickness, as the die angle α increases, the Mises stress increases significantly. As the wall thickness increases, the peak value of the expansion force increases significantly. The finite element simulation model established in this study can accurately predict the size of the TiNiFe alloy ring after expansion, evaluate the stress and strain state during the expansion process, and provide data support and theoretical guidance for subsequent applications.