人工心瓣热解炭断裂韧性有限元分析.pdf

31卷6期
中国生物医学工程学报
2012年12月
Chinese Journal of Biomedical Engineering
December 2012
人工心瓣热解炭断裂韧性有限元分析
张建辉”邢兴
(杭州电子科技大学机械工程学院,杭州310018)
摘要:利用有限元分析软件 ANSYS,对人工心瓣各向同性热解炭和热解炭包覆石墨复合材料进行紧凑拉伸以及
三点弯曲实验仿真分析,计算材料的平面应变断裂韧性K,并将计算结果与相关实验结果进行对比,分析利用
ANSYS计算Kに方法的有效性,以及涂层与基体厚度比、裂纹尖端半径对热解炭包覆石墨复合材料Kc值的影响。
结果表明,纯热解炭和石墨材料的 ANSYS计算Kに值分别为1.176 Mpam以及1.415 Mpam,与相关实验结果接
近,验证了 ANSYS计算KC值的准确性;热解炭包覆石墨复合材料的计算Kc值随涂层与基体厚度比的增加而降
低,涂层与基体厚度比偏低时,复合材料断裂性能均优于纯热解炭和石墨材料;热解炭包覆石墨材料存在临界裂纹
尖端半径po(约5um)。当裂纹尖端半径p>p0时,Kc测量值与p2成正比;a量值一致
关键词:热解炭;热解炭包覆石墨; ANSYS;断裂韧性
中图分类号R318文献标志码A文章编号0258-8021(2012106-0889-06
Finite Element Analysis of Fracture Toughness of Pyrolytic
Carbon in Prosthetic Heart Valve
ZHANG Jian-hui XING Xing
School of Mechanieal Engineering, Hangthou Dianzi University, Hangthou 310018, China)
Abstract This article used ANSYS to conduct simulation analysis of compact tension and 3 points bending test
for the isotropic pyrolytic carbon and pyrolytic carbon-coated graphite composite material used in heart valve
prosthesis, calculated the plane strain fracture toughness Kc and compared the calculated results with the
of related experiments, then analyzed the effectiveness of the method that used ANSYS to calculate K
as well as the influence of the thickness ratio of the coating and substrate and crack tip radius for the Kc of
pyrolytic carbon-coated graphite composite material. Results showed that the Kuc of the pure pyrolytic carbon
and graphite material were respectively 1 176 Mpa m and 1.415 Mpa m, which were close to the results of
related experiments, verifying the accuracy of using ANSYS to calculate Kc; the Kic of composite material of
rolytic carbon-coated graphite reduced with the increase of thickness ratio for the coating and substrate. The
fracture toughness of composite material was better than that of pure pyrolytic carbon or graphite composite
material when the thickness ratio of coating and substrate was on the low side; pyrolitic carbon-coated graphite
had a limit notch root radius p, which was about 5 wm, when the notch root radius p >Po, the measured value
of K was proportional to p", and when p samples with sharp crac
Key words:: pyrolytic carbon; pyrolytic carbon-coated graphite; ANSYS; fracture toughness
dai:1,3969/j,isa.02588021.2012.06.013
收稿日期:2012-06-30,录用日期:2012-08-2
基金项目;国家自然科学基金(50975070);浙江省自然科学基金(LY12EO5002)
通信作者。E-mail: zhangju@hdu,edu