非对称椎动脉支架变形机理的有限元分析

The Research Based on the Finite Element Analysis on the Mechanism of the Asymmetric Deformation of the Vertebral Artery Stents

利用有限元方法研究一种非对称结构椎动脉支架的动静态耦合扩张过程。应用ABAQUS软件分析支架在静态变形过程中的应力应变变化规律;计算支架径向回弹率、轴向缩短率、左右端扩张不均匀性等生物力学性能,以及模拟分析支架在脉动循环的血压下的疲劳强度,并用Goodman准则评价支架的疲劳寿命。结果表明:支架各项力学性能都在临床允许的范围内,由Goodman评价准则发现最危险点分布在支撑体过渡圆弧的内侧,且在材料疲劳极限安全区域内,在相当10年寿命内整个结构不发生断裂。该结构支架为椎动脉狭窄的支架介入研究提供良好的参考。

The paper has used the finite element method to study the expansion process for a dynamic and static coupling of asymmetric structure vertebral artery stents. The stents are analyzed by ABAQUS software for the stress and strain changing rule in the static deformation process. The biomechanieal properties such as the stent radial rebound rate, axial shortening rate, and unevenness of both ends expansion are calculated. The simulation analyzes the fatigue strength of stents under the alternate circulation of the blood pressure. The Goodman criteria is used to evaluate the fatigue life. The results show that the various mechanical properties of sent are in clinical allowable range. With the Goodman evaluation criteria, the most dangerous point is distributed inside the transition circular are of the supporting body, and also in the security area of the material fatigue limit. Within quite 10 years the entire structure will not break. This structure provides a good reference for vertebral artery stenosis stent intervention studies.