Computational Studies of Shape Memory Alloy Behavior in Biomedical Applications

Background: Nowadays, shape memory alloys (SMAs) and in particular Ni–Ti alloys are commonly used in bioengineering applications as they join important qualities such as resistance to corrosion, biocompatibility, fatigue resistance, and kink resistance with two unique thermo-mechanical behaviors: the shape memory effect and the pseudoelastic effect, allowing Ni–Ti devices to undergo large mechanically induced deformations and recover the original shape by thermal loading or mechanical unloading. Objective: This study aims to develop a numerical model to capture the significant SMA macroscopic thermo-mechanical properties for biomedical device simulations. Methodology: The model is implemented into a commercial finite element code for simulating biomedical device behavior. Results: The comparison between the experimental and numerical response of an intravascular coronary stent demonstrates the model's capability to describe pseudo-elasticity. Furthermore, the numerical evaluation of a spinal vertebrae spacer reveals the model's efficacy in illustrating the shape memory effect by investigating different geometries and material characteristic temperatures. Conclusion: The results presented underscore the critical role of computational studies in the design and optimization of innovative biomedical devices.