李红霞 张艺浩 王希诚

中文摘要:
      目的 利用有限元方法研究支架在狭窄血管内的扩张性能、支架内血流动力学状况和支架的疲劳寿命。方法 采用ANSYS模拟支架在狭窄血管内的扩张过程，提取扩张后相关节点数据，建立血流动力学分析模型，并建立与之对应的简化模型，模拟分析支架内血流动力学状况。分别基于Goodman图表和累计损伤法，对支架的疲劳寿命进行评估。结果 （1） 支架上绝大部分部位发生塑性变形，主要应力发生在镂空孔的角点。（2） 支架附近流动紊乱,血流流入端的桥接支柱附近应力最高。（3） Goodman图表法表明该支架是安全的，累计损伤法表面支架在血流流入端桥接支柱所在的第2个横截面上累计损伤最大。结论 有限元方法能有效地应用于支架扩张、支架内血流动力学以及支架的疲劳模拟仿真。
英文摘要:
      Objective To study the expansion behavior of stent in stenotic vascular, instent blood flow and fatigue life of stent by finite element method. Methods ANSYS was used to simulate the expansion of stent in stenotic vascular. The blood flow model was created by constructing the entities based on deformation of the related nodes from the result of dilation process. A sample model was also built to simulate the instent blood flow. Stent fatigue life was evaluated based on Goodman’s method and accumulated damage method, respectively. Results (1) Plastic deformation appeared on most parts of struts. The major stresses were localized in the corner of the slots. (2) Turbulent flow occured near the stent. Stresses of stent in crosssection of bridge struts along the direction of blood flow were highest. (3) Goodman’s method showed that the stent was safe, and cumulative damage indicated that the largest cumulative damage occured in the second crosssection of bridge struts. Conclusions Finite element method can be effectively used to simulate the stent expansion, instent blood flow and stent fatigue life.