Numerical Analysis of Vascular Stents Exploiting Shape-memory-alloy Behavior

Shape Memory Alloys (SMA) have the unique capability to recover the original shape, once mechanically deformed, through mechanical unloading, Superelastic Effect (SE), or through thermal loading, Shape Memory Effect (SME). These peculiar behaviors, coupled with a good material biocompatibility, have stimulated a wide diffusion of SMA in the area of biomedical devices. In this work we numerically investigate the SMA performance in stent vascular applications. In particular, adopting a numerical algorithm describing the SMA thermo-mechanical behavior (Auricchio and Petrini, International Journal for Numerical Methods in Engineering, 2002), we compare the behavior of a self-expandable (SE) SMA stent during the expansion in a stenotic artery with that of a balloonexpandable stainless steel stent. Moreover, we study the response of a balloon-expandable SMA stent where SME is exploited for removing the device. The aim is to verify the model ability to describe the behavior of SMA biomedical devices as well as to show the utility of finite element analyses to give indications both to clinicians and manufactory firms. AIMETA ‘03 XVI Congresso AIMETA di Meccanica Teorica e Applicata 16 AIMETA Congress of Theoretical and Applied Mechanics