镍钛合金支架关键尺寸对其疲劳性能影响的有限元分析

发布时间：2018-11-21 12:20

【摘要】：为了对镍钛合金支架的疲劳性能进行评价,使用Ansys软件模拟支架生产过程中的扩张、热处理和压握等工序以及临床使用的释放过程,分析了不同圆弧段尺寸对支架结构中应变分布的影响,并采用疲劳图谱来研究具有不同支架圆弧段尺寸的镍钛合金支架的疲劳特性。本文研究发现:在承受血管载荷时,具有不同圆弧段尺寸的三种支架结构的最大主应变均分布于圆弧段和支架杆相交的过渡点附近区域;但是当圆弧段尺寸与支架杆尺寸相等时,在圆弧段中心内侧位置也有很大的应变出现。这是由于圆弧段尺寸的差异引起了镍钛合金支架杆截面惯量的差异,从而导致支架结构中应变分布区域的不同。此外,由疲劳图谱可知当支架圆弧段尺寸取值为中间值时,其疲劳安全性却是最好的。以上结果说明镍钛合金支架的疲劳性能与其圆弧段几何尺寸密切相关,但并不是正相关关系。
[Abstract]:In order to evaluate the fatigue performance of Ni-Ti alloy scaffolds, Ansys software was used to simulate the process of expansion, heat treatment and grip, as well as the release process in clinical use. The effects of different arc sizes on the strain distribution in the support structure were analyzed and the fatigue characteristics of Ni-Ti alloy scaffolds with different arc sizes were studied by fatigue diagram. In this paper, it is found that the maximum principal strain of three kinds of scaffold structures with different arc-segment sizes are distributed near the transition point between the arc segment and the support rod when subjected to vascular loading. However, when the arc section size is equal to the support bar size, there is also a large strain in the center of the arc segment. This is due to the difference in arc size, which leads to the difference of inertia of nickel titanium alloy bracket, which leads to the difference of strain distribution region in the support structure. In addition, the fatigue safety is the best when the size of the arc segment of the bracket is the middle value. The above results show that the fatigue properties of Ni-Ti alloy support are closely related to the geometric size of the arc segment, but are not positively correlated.
【作者单位】：复旦大学力学与工程科学系;
【基金】：国家自然科学基金资助项目(11102042)
【分类号】：R318.08

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