摘要
可降解镁合金支架(MAS)能够改善商用裸支架和药物洗脱支架的长期治疗效果。由于镁合金支架在人体内降解速度太快,限制了其对病变血管的支撑性能。保护性聚合物涂层为镁合金支架提供了一种降低腐蚀速度的有效方法。然而,聚合物涂层在支架扩张时出现的剥离现象是阻碍其运用的一大障碍。在本研究中,分别运用有限元方法和实验方法对一种优化设计的镁合金支架进行了聚合物涂层剥离问题的研究。首先通过90o剥离实验测试,为粘聚区有限元模型提供了临界能量释放率,以此为基础的90o剥离的模拟结果和实验结果吻合良好。运用可靠的粘聚区模型参数,支架-聚合物涂层有限元模型考察了支架在扩张过程中是否会发生涂层剥离现象。本研究为考察支架聚合物涂层剥离现象提供了一种简单可靠的方法,为改善可降解镁合金支架的聚合物涂层性能提出了相应的建议。
Biodegradable magnesium alloy stems （MAS） could improve the long-term clinical results of commercial bare metal or drug-eluting stents. MAS have shown a limited mechanical support for diseased vessels due to fast degradation. Protective polymer coating is a reasonable way to reduce the degradation rate of MAS. However, peeling of the coating during stent expansion is the main obstacle in stent application. In this study, experimental and computational methods were used to study the peeling problem of an optimized MAS design. The 90~ peeling test provided the critical energy release rate with cohesive zone method to be used in the simulation study; the 90° peeling modeling had good agreement with the experimental test. Using reliable cohesive element material parameters, the simulation could verify whether the peeling happened when the coated MAS was expanded. The aim of this study is to provide an easy and reliable method to approach peeling problem of MAS, giving the instructions for the improvement of MAS coatings.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2014年第12期2877-2882,共6页
Rare Metal Materials and Engineering
基金
Fondazione CaRiTRO(2011.0250)
Politecnico di Milano International Fellowships Program(PIF)
关键词
镁合金支架
涂层
有限元分析
粘聚区模型
剥离
magnesium alloy stent
coating
finite element analysis
cohesive zone method
peeling
