Fatigue Strength Study and Life Prediction of Two Nickel-Titanium Alloy Stents for Left Ventricular Reconstruction
Left ventricular reconstruction is an effective method for treating heart failure,with the implants of a nickel-titanium alloy stent into the left ventricle.In order to solve the problem that the stent cannot be positioned multiple times during surgery and cannot be recycled,a stent with double-layer structure has been studied and iterative design has been conducted.Then the fatigue performance of the first-generation stent and the iteratively designed stent was compared.The results show that the mesh intersection of the upper skeleton of the first-generation stent is prone to stress concentration and fatigue fracture,while the peak equivalent stress of the iteratively designed stent is only 82%～90%of the first-generation model,and the possibility of fatigue fracture failure caused by stress concentration is less than the first-generation model.The alternating strain part of the first-generation stent exceeds the fatigue limit and cannot meet the postoperative fatigue life requirements,while the alternating strain of the iteratively designed stent is all less than the fatigue limit,which can meet the postoperative fatigue life requirements.The life of the iteratively designed stent is 4.84 times that of the first-generation stent,with predicted fatigue life of 14 years.In summary,the fatigue strength and fatigue life of the iteratively designed stent can meet the requirements after left ventricular reconstruction surgery.
nickel-titanium alloyrecyclable stentfinite element analysisfatigue life prediction
NETL
NSTL
万方数据
