Innovative and efficient stent flexibility simulations based on isogeometric analysis

One of the main properties of cardiovascular stents is to properly bend in order to accommodate the tortuous vascular structure and Finite Element Analyses (FEA) are currently the preferred computational tool to properly evaluate the stent response under bending. Isogeometric Analysis (IgA) has recently emerged as a cost-effective alternative to classical FEA, based on the use of typical CAD basis functions for both geometric description and variable approximation. This implies the capability to describe accurately the computational domain geometry and, typically, a better approximation of the solution with many fewer degrees of freedom with respect to FEA.Accordingly, this work aims at describing a computational framework based on IgA to evaluate the mechanical performance of endovascular stents. In particular, stent bending analyses involving large deformations are performed using both IgA and classical FEA for two carotid artery stent designs. The results discussed here suggest that for a given level of accuracy IgA attains a better performance with at least one order of magnitude fewer degrees of freedom than classical FEA. Moreover IgA shows an improved capability to reproduce local geometrical instabilities due to buckling.