考虑到低镍不锈钢的高强度和优异的生物相容性,本文的重点是使用有限元分析(FEA)结合响应面法(RSM)对由该材料制成的血管支架进行优化设计。目的是在保持薄的支架壁厚的同时实现支架的期望的压缩阻力。支架支撑单元宽度(H)的参数,支柱宽度(W),选择厚度(T)作为输入参数,而从有限元分析获得的输出参数包括压缩载荷,等效塑性应变(PEEQ),轴向缩短率,径向反冲率,和金属覆盖率。利用RSM的BoxBehnken设计(BBD)建立了输入参数和输出参数的数学模型。模型方程在约束条件下求解,和最佳结构参数,即H,W,T,最终确定为0.770毫米,0.100mm,和0.075毫米。在这种情况下,支架的压缩载荷达到目标值0.38N/mm;支架扩张导致的PEEQ较小;轴向缩短,径向反冲,和金属覆盖指数都在所需范围内最小化。
Considering the high strength and excellent biocompatibility of low-nickel stainless steel, this paper focused on optimizing the design of a vascular stent made from this material using finite element analysis (FEA) combined with the response surface methodology (RSM). The aim is to achieve the desired compressive resistance for the stent while maintaining a thin stent wall thickness. The parameters of the stent\'s support unit width (H), strut width (W), and thickness (T) were selected as input parameters, while the output parameters obtained from FEA included the compressive load, the equivalent plastic strain (PEEQ), axial shortening rate, radial recoil rate, and metal coverage rate. The mathematical models of input parameters and output parameters were established by using the Box Behnken design (BBD) of RSM. The model equations were solved under constrained conditions, and the optimal structural parameters, namely H, W, and T, were finally determined as 0.770 mm, 0.100 mm, and 0.075 mm respectively. In this situation, the compression load of the stent reached the target value of 0.38 N/mm; the PEEQ resulting from the stent expansion was small; the axial shortening, radial recoil, and metal coverage index were all minimized within the required range.