两种左心室重建镍钛合金支架的疲劳强度研究和寿命预测  

Fatigue Strength Study and Life Prediction of Two Nickel-Titanium Alloy Stents for Left Ventricular Reconstruction

作　　者：周炬[1] 叶江[1] 滕浩 ZHOU Ju;YE Jiang;TENG Hao(College of Mechanical Engineering,University of South China,Hengyang 421001,China)

机构地区：[1]南华大学机械工程学院,湖南衡阳421001

出　　处：《机械》2024年第12期19-25,共7页Machinery

基　　金：湖南省教育厅科学研究项目(22C0222)。

摘　　要：左心室重建术以镍钛合金支架植入左心室中,是一种有效治疗心衰的方法。为突破现有支架在术中不可多次定位和不可回收的问题,研究了双层结构支架,并进行迭代设计。对初代支架和迭代设计后支架进行疲劳性能对比。结果表明,初代支架上层骨架的网状交叉处易产生应力集中,易出现疲劳断裂,而迭代设计后支架峰值等效应力仅为初代模型的82%~90%,应力集中导致的疲劳断裂失效可能性小于初代模型;初代支架部分节点的交变应变超出疲劳极限,不能满足术后疲劳寿命要求,而迭代设计后支架全部节点的交变应变均小于疲劳极限,可以满足术后疲劳寿命要求;迭代设计后支架的疲劳寿命为初代支架寿命的4.84倍,预测其为14年的疲劳寿命。综合上述结果,迭代设计后支架的疲劳强度和疲劳寿命均可满足左心室重建术后要求。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.

关 键 词：镍钛合金 可回收支架 有限元分析 疲劳寿命预测 

分 类 号：O346.23[理学—固体力学]