Finite element modeling of SMA stent insertion in the vessel with consideration of vessel damage

Deposition of fatty substances and calcium in the artery is one of the factors that cause decrease of blood supply to the organs of the body. One of the common methods to resolve artery stenosis is insertion of a shape memory alloy (SMA) stent in the artery. The use of shape memory alloys in the manufacturing of self-expandable stent has expanded because of the superelastic behavior of this alloy. In this paper, we simulated the SMA stent insertion in an artery to explore stress and damage effects arising from the stent insertion on the artery by using ABAQUS software. In order to simulate mechanical behavior of artery, we considered the effect of the inelastic arterial properties (stress softening and recoverable inelastic deformation) that activated under supra physiological loading in stenting process and in order to simulate stent behavior, the Souza model is used. These two models were applied in ABAQUS by UMAT codes. By using damage model, the amount of damage in the artery, which is one of the factors of restenosis, is investigated. Also, in this paper, we use real diseased artery geometry, which were specified from high resolution Magnetic Resonance Images, therefor the analysis is more in line with reality and it is possible to determine the location of the maximum stress and damage in the artery.