Fatigue Analysis of Nitinol Peripheral Artery Stents Under Complex Loads

Abstract

The complex deformation of a peripheral arterial stent during limb movements is the main reason for its fatigue fracture. The aim of this study is to explore the impact of complex loads on the fatigue behavior and life of lower limb arterial stents. Specifically, the finite element simulation was adopted to compare and analyze the fatigue performance of three stents under five superimposed loads. Besides, the life and the fatigue crack growth life of these stents were predicted. It demonstrated that the bending load superimposed on other loads exerted a significant impact on the fatigue performance of these stents. The “spiral” structure design of the stent helped to improve the fatigue durability under complex deformations. Moreover, the prediction method for fatigue crack growth life is relatively conservative, which accounted for approximately 65–97% of the full life. The work provides important references for the fracture assessment and the optimization design of structure of stents.