ABSTRACT

Shape memory alloy (SMA) has been widely applied in biomedical engineering because it has two unique characteristics: superelasticity and shape memory effect. The corresponding finite element SMA material models have been developed to simulate their mechanical behavior in the commercial software. In this chapter, angioplasty with vascular stenting was studied using the SMA superelasticity material model, involving three steps: (1) deactivate the contact between the vessel and the stent and apply pressure to the wall of the vessel to make the vessel and plaque swell; (2) activate the contact between the vessel/plaque and the stent; and (3) reduce the applied pressure to reach normal blood pressure. The third step costs the major computational time because of hard convergence of the contact between the vessel/plaque and the stent. The computation results illustrate that the stent makes the plaque expand from an initial radius of 1.5 mm to one of 1.9 mm, which allows more blood to flow into the vessel. Also, the existence of the plastic strain of the stent indicates that the phase transformation of SMA occurs.