Mechanical modeling of self-expandable stent fabricated using braiding technology
Mechanical modeling of self-expandable stent fabricated using braiding technology
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DOI：
10.1016/j.jbiomech.2008.08.005
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发表时间：
2008-11-14
影响因子：
2.4
通讯作者：
Yu, Woong-Ryeol
中科院分区：
文献类型：
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作者：
Kim, Ju Hyun;Kang, Tae Jin;Yu, Woong-Ryeol
支架的机械性能是确保其在动脉导管内打开的重要因素之一。本研究旨在开发一种用于设计使用编织技术制造的自膨胀支架的力学模型。为此，通过开发支架内部编织结构三维几何建模的前处理程序，建立了有限元模型，并对不同编织结构的支架进行了验证。假设编织支架中的组成金属丝（镍钛合金）为超弹性材料，并通过使用一维超弹性模型的用户材料子程序（ABAQUS中的VUMAT）将其机械行为纳入有限元软件中。为了验证模型，使用自动编织机制造了几个编织支架，并重点对其压缩行为进行了表征。观察到当压缩载荷施加到编织管时，编织支架在其加载和卸载行为之间显示出滞后。通过有限元分析，得出的结论是，当前的力学模型可以适当地预测编织支架的力学行为，包括这种滞后行为，滞后是由组成丝之间的滑移和它们的超弹性特性引起的。(C)2008爱思唯尔有限公司保留所有权利。
The mechanical behavior of a stent is one of the important factors involved in ensuring its opening within arterial conduits. This study aimed to develop a mechanical model for designing self-expandable stents fabricated using braiding technology. For this purpose, a finite element model was constructed by developing a preprocessing program for the three-dimensional geometrical modeling of the braiding structure inside stents, and validated for various stents with different braiding structures. The constituent wires (Nitinol) in the braided stents were assumed to be superelastic material and their mechanical behavior was incorporated into the finite element software through a user material subroutine (VUMAT in ABAQUS) employing a one-dimensional superelastic model. For the verification of the model, several braided stents were manufactured using an automated braiding machine and characterized focusing on their compressive behavior. It was observed that the braided stents showed a hysteresis between their loading and unloading behavior when a compressive load was applied to the braided tube. Through the finite element analysis, it was concluded that the current mechanical model can appropriately predict the mechanical behavior of braided stents including such hysteretic behavior, and that the hysteresis was caused by the slippage between the constituent wires and their superelastic property. (C) 2008 Elsevier Ltd. All rights reserved.