Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow, G1 1XJ, UK.
MedAlliance, Glasgow, G52 4GA, UK.
Ann Biomed Eng. 2020 Jan;48(1):144-156. doi: 10.1007/s10439-019-02322-0. Epub 2019 Jul 17.
Ring stent bundles have been used in several biomedical stent-graft devices for decades, yet in the published literature, the numerical models of these structures always present significant simplifications. In this paper, a finite element (FE) ring stent bundle has been developed and evaluated with a combination of beam and surface elements. With this approach, the shape, the global stiffness and the strains of the structure can all be well predicted at a low computational cost while the approach is suitable for application to non-symmetrical, patient-specific implant simulations. The model has been validated against analytical and experimental data showing that the manufacturing strains can be predicted to a 0.1% accuracy and the structural stiffness with 0-7% precision. The model has also been compared with a more computationally expensive FE model of higher fidelity, revealing a discrepancy of 0-5% of the strain value. Finally, it has been shown that the exclusion of the manufacturing process from the simulation, a technique used in the literature, quadruples the analysis error. This is the first model that can capture the mechanical state of a full ring stent bundle, suitable for complex implant geometry simulations, with such accuracy.
环形支架束已在数十年来在几种生物医学支架移植物装置中使用，但在已发表的文献中，这些结构的数值模型始终存在显著的简化。在本文中，使用梁和表面单元的组合开发并评估了有限元（FE）环形支架束。通过这种方法，可以以较低的计算成本很好地预测结构的形状、整体刚度和应变，并且该方法适用于非对称、针对特定患者的植入物模拟。该模型已通过分析和实验数据进行了验证，表明可以将制造应变的预测精度提高到 0.1%，结构刚度的预测精度提高到 0-7%。该模型还与具有更高保真度的更计算密集型 FE 模型进行了比较，显示应变值的差异在 0-5%之间。最后，结果表明，从模拟中排除制造过程（文献中使用的技术）会将分析误差增加四倍。这是第一个能够以如此精度捕获完整环形支架束机械状态的模型，适用于复杂的植入物几何形状模拟。
