A fracture-mechanics-based approach to fracture control in biomedical devices manufactured from superelastic Nitinol tube.
A fracture-mechanics-based approach to fracture control in biomedical devices manufactured from superelastic Nitinol tube.
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一种基于断裂力学的方法，用于控制由超弹性镍钛诺管制造的生物医学设备的断裂。
DOI：
10.1002/jbm.b.30840
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
R. Ritchie
中科院分区：
文献类型：
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作者：
S. W. Robertson;R. Ritchie
最近报告了超弹性合金镍钛诺的几个与亚临界和临界裂纹发生相关的关键断裂力学参数，特别是断裂韧性、抗裂曲线和疲劳阈值，其产品形式为薄壁管，用于制造几种生物医学器械，最值得注意的是血管内支架。在这项研究中，我们使用这些关键参数来构建简单的决策标准，以评估此类镍钛合金器械中裂纹样缺陷对其变形或断裂失效抗力的定量影响。该标准基于（等效）裂纹萌生断裂韧性和疲劳阈值应力强度范围，以及一般屈服强度和疲劳持久强度，并用于构建针对单次事件（过载）失效以及与疲劳相关的时间/周期延迟失效的设计基础。
Several key fracture-mechanics parameters associated with the onset of subcritical and critical cracking, specifically the fracture toughness, crack-resistance curve, and fatigue threshold, have recently been reported for the superelastic alloy Nitinol, in the product form of the thin-walled tube that is used to manufacture several biomedical devices, most notably endovascular stents. In this study, we use these critical parameters to construct simple decision criteria for assessing the quantitative effect of crack-like defects in such Nitinol devices with respect to their resistance to failure by deformation or fracture. The criteria are based on the (equivalent) crack-initiation fracture toughness and fatigue threshold stress-intensity range, together with the general yield strength and fatigue endurance strength, and are used to construct a basis for design against single-event (overload) failures as well as for time-/cycle-delayed failures associated with fatigue.