M型Ti-Ni合金血管支架的结构设计对性能的影响

Influence of Structural Design of M Type Ti-Ni Alloy Vascular Stents on Performance

血管支架的支撑性能及回弹性能是支架在结构设计过程中需要考虑的重要指标。本文选取M型支架节,通过有限元软件模拟,探究M型支架节的高度变化及结构设计波高比(h/H)对支架支撑性能及回弹性能的影响。结果显示:相同h/H比值的M型结构设计,支架高度H值越小,支架支撑力越大;固定高度H值不变,随着h/H比值增大,支架的支撑力减小,且在同一位移载荷下,减小程度随h/H比值增大更显著;当h/H=1时,M型支架转变为Z型支架,此时支架的支撑力最小;不同h/H比值设计的M结构,在不同的位移载荷作用下支架的回弹率区别较大;以h/H=1/2为基准,h/H<1/2的支架结构较h/H>1/2的支架结构回弹率明显高;在不同的位移载荷作用下,Z型支架较M型支架支撑性能较弱但回弹率稳定。

Vascular stents＇ support performance and resilience are important indicators that should be taken into account in the design process. In this research,M type stents were selected. The influence of the height change of M type stent section and the ratio of height proportion design（h/H） on support performance and resilience was explored through finite element simulation. The results showed that with the same ratio of h/H structural design,the smaller value of the height H of stents was,the greater the supporting force would be.Keeping the values of height H unchanged,with the ratio of h/H ratio increasing,the supporting force reduced and the degree turned to be more prominent under the same displacement load. When h/H = 1,the type of M stent transformmed into Z type and the value of supporting force was minimum at this time. The type of M structure designed with different ratios of h/H,the stents＇ resilient rate was highly different under different displacement loadings; based on h/H = 1/2,the resilient rate of the structure with h/H〈 1/2 was significantly higher than that of the structure with h/H 〉1/2. Z type stents had weaker supporting performance and more stable resilience than M type stents under different displacement loadings.