中文摘要：

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KIC,并将计算结果与相关实验结果进行对比,分析利用ANSYS计算KIC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KIC值的影响。结果表明,纯热解炭和石墨材料的ANSYS计算KIC值分别为槡1.176 MPa m以及槡1.415 MPa m,与相关实验结果接近,验证了ANSYS计算KIC值的准确性;热解炭包覆石墨复合材料的计算KIC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ρ0（约5μm）。当裂纹尖端半径ρ〉ρ0时,KIC测量值与ρ^1/2成正比;ρ〈ρ0时,KIC测量值与尖锐裂纹样品测量值一致。

英文摘要：

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 KIC and compared the calculated results with the results of related experiments,then analyzed the effectiveness of the method that used ANSYS to calculate KIC as well as the influence of the thickness ratio of the coating and substrate and crack tip radius for the KIC of pyrolytic carbon-coated graphite composite material.Results showed that the KIC of the pure pyrolytic carbon and graphite material were respectively 1.176 MPam and 1.415 MPam,which were close to the results of related experiments,verifying the accuracy of using ANSYS to calculate KIC;the KIC of composite material of pyrolytic 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 ρ0,which was about 5 μm,when the notch root radius ρρ0,the measured value of KIC was proportional to ρ^1/2,and when ρρ0,the measured value of KIC was in line with the value of samples with sharp crack.