マグネシウム合金の弾塑性挙動と負荷経路を考慮したステントのデザイン最適化

抄録

Magnesium alloys have biocompatibility, so their application to medical devices is progressing. However, magnesium is HCP structural material and exhibits peculiar deformation behavior such as the SD (Strength-differential) effect. In order to design a magnesium product optimally, the special material characteristics of magnesium and the load history that the product need to be considered together. In this study, by performing finite element method analyses on a stent model using the material properties of magnesium alloys, some useful information to create optimal product shapes is obtained. Considering the SD effect, it was found that there is an apparent difference in maximum stress and strain distributions during bending and expanding simulations, which suggests there is an optimal shape. Namely, when the SD effect is introduced in the simulation, a structure optimization technique revealed the suitable shape with reduced curvature that can avoid excessive compressive stresses.