Finite element analysis of coupling force for TiNiFe shape memory pipe coupling

Shape memory alloy (SMA) is widely used in aerospace devices, and shape memory pipe coupling is one of the most successful SMA applications. Dimension design is a key aspect for shape memory pipe coupling, and determines the connecting strength of the connecting system. Numerical simulation provides a theoretical basis for dimension design. In this paper, finite element method (FEM) is used to simulate the coupling force of the connecting system. In the simulation, material property parameters of titanium-nickel-iron ( TiNiFe) SMA are measured from experiments. Three-dimensional analysis for pipe coupling is performed with a thermo-mechanical model. The influence of inner diameter, expansion ratio of diameter and operating temperature on the radial stress of the connecting system was investigated. The results of the simulation are used to guide the adjustment of parameters such as the inner diameter and the expansion ratio of diameter for the purpose of maximizing the connecting strength.