中文摘要：

针对工程实际上更为常见的复合型裂纹,建立基于弹性断裂理论和复变函数理论的能量计算模型。研究裂纹扩展过程中,系统能量在各种相关因素影响下的变化规律。以I、II型复合裂纹为例,采用能量释放率理论对外荷载、裂纹所处角度及裂纹的几何尺寸等因素对系统能量的影响进行全面的仿真计算。同时,基于复合裂纹与I型裂纹在裂纹转动角度上的不同,对复合型裂纹和I型裂纹系统能量的变化进行比较。结果表明：系统能量随着外荷载和裂纹所处角度的增加而增大;随着裂纹长度增大而减小。当外荷载、裂纹长度为零时,系统能量也为零。当裂纹由I型裂纹产生一个转动角度时,系统能量是增加的。在同样的荷载条件、边界条件进行分析,具有转动角的复合型裂纹能量较I型裂纹的系统能量大。

英文摘要：

Aiming at the mixed mode crack,which is commonplace in practical engineering,an energy calculation model based on elastic fracture theory and complex variable function theory is built in order to study the change law of system energy under the effects of various relative factors,during crack propagation.Taking the I,II mixed mode crack for example,the effects of external load,crack angle,geometrical sizes of crack and others factors on system energy are calculated completely.The change of system energy of mixed mode crack is compared with that of mode I crack based on different crack angle.It is shown that with the increasing of external load and crack angle,the system energy increases.And with the increasing of crack length,the system energy decreases.When the external load and crack length equal to zero,the energy also equals to zero.Moreover,at the same external load and boundary conditions,the energy of mixed mode crack with certain crack angle is bigger than I mode crack.