Stent Fracture Predictions With Peridynamics

Abstract

Currently, stent therapy constitutes to over 95% of all endovascular interventions. The biological and clinical complications of stent therapy can now be well controlled with modern techniques and procedures. However, the mechanical failure of stent remains an important clinical problem [1]. While there is a consensus that such failure usually proceeds through mechanical fracture activation due to fatigue, the mechanisms of fracture activation are not well understood. The virtual analysis of fracture is typically conducted using the Finite Element Method (FEM) model regulated by the externally applied criteria of fracture nucleation. Typically, the FEM model must deal with ambiguity of derivatives of displacement at discontinuities and should contain requirements on mesh size to resolve material damage. In this study, we pursue an alternative approach, called peridynamics, to depict the mechanism of fracture activation. Peridynamic damage model does not require special criteria to guide crack or damage growth and naturally accounts for surface roughness that can highly influence fatigue life of stent.