Bi - material interfacial fracture theories are researched with a phenomenon that cracks extend along interface . a gradient invading model of interface crack at the crack tip can gain stress fields along interface . so a formula of energy release rate for 3d braided cmc is deduced and the corrected formula of the energy release rate is examined with test results 研究了裂纹沿界面扩展的双材料界面断裂理论，利用倾斜侵入界面的裂纹模型解析了裂纹尖端沿着界面的应力场，推导了表征三维编织cmc复合材料断裂韧性的能量释放率公式g _ c ，并且用试验结果验证了能量释放率公式的正确性。
