Thermo-mechanical numerical analysis of stent unit cell

Abstract

This paper aims to highlight importance of coupled thermo-mechanical analysis of structures and devices made of shape memory alloys (SMA). Ti-Ni alloys are recognized as very biocompatible SMA, so theirs usage is very often in medical purpose. Stent implants made of SMA are the best known application of such materials, so the unit cell of some typical stent model is used to demonstrate the necessity of coupled finite element based numerical analysis of such structures. The thermo-mechanical coupling is realized in partitioned approach, whereas software components for structural analysis (PAKS) and heat transfer (PAKT) have been used as suitable solutions. The SMA constitutive model is implemented into PAKS with the capability to solve large strain problems by using multiplicative decomposition of deformation gradient.