热解炭表面复合型裂纹初始起裂角研究

Research on initial crack initiation angle of compound cracks on the surface of pyrocarbon

为了研究人工心瓣热解炭涂层表面半椭圆形微小裂纹的扩展行为,采用ABAQUS有限元分析与FRANC3D断裂分析软件对人工心瓣热解炭涂层表面半椭圆形中心裂纹初始起裂角进行仿真分析。研究结果表明:Ⅰ型和Ⅱ型裂纹初始起裂角在裂纹前缘中心取得最小值,在裂纹尖端取得最大值;裂纹深度不变时,Ⅰ型裂纹初始起裂角随裂纹倾斜角的增大而增大,Ⅱ型裂纹初始起裂角随裂纹倾斜角的增大先减小后增大;裂纹倾斜角不变时,裂纹深度越小,对模型表面裂纹初始起裂角的影响越大,且裂纹深度对Ⅰ型裂纹初始起裂角的影响大于Ⅱ型裂纹。

In order to study the propagation behavior of the micro-cracks on the surface of artificial heart valve pyrocarbon coating,ABAQUS finite element analysis and FRANC3D fracture analysis software were used to simulate the initial crack initiation angle of semi-elliptical central cracks on the surface of artificial heart valve pyrocarbon coating.The results show that the initial crack initiation angles of mode Ⅰ and mode Ⅱ reach the minimum at the crack center and the maximum at the crack tip;when the crack depth is constant,the initial crack initiation angle of mode Ⅰ increases with the increase of the crack inclination angle,and the initial crack initiation angle of mode Ⅱ decreases first and then increases with the increase of the crack inclination angle;under the condition that the crack inclination angle is constant,the smaller the crack depth,the greater the influence on the initial crack initiation angle of the front edge in the model surface,and the influence of the crack depth on the initial crack initiation angle of mode Ⅰis greater than that of mode Ⅱ.