中文摘要：

为了探究复合型裂缝的应力强度因子K和应变能释放率G的关系，基于最大应力准则，采用能量法对Ⅰ-Ⅱ复合型裂缝的扩展进行理论分析。根据单一型裂缝应力强度因子和应变能释放率的关系，推导出Ⅰ-Ⅱ复合型裂缝K与G的关系公式，利用Abaqus软件建立Ⅰ-Ⅱ复合型裂缝的有限元模型，计算Ⅰ-Ⅱ复合型裂缝的应力强度因子和应变能释放率，与推导公式的计算结果进行对比，二者误差仅为2．5％，验证了推导公式的合理性。

英文摘要：

In order to study the relationship between stress intensity factor and strain energy release rate of mixed mode cracks, the growth of Ⅰ-Ⅱ mixed mode cracks is theoretically analyzed by means of the energy method based on the maximum stress criterion. A formula for the relationship between the stress intensity factor and the strain energy release rate of the Ⅰ-Ⅱ mixed mode cracks is deduced according to the available relationship between the stress intensity factor and the strain energy release rate of single mode crack. A FEM model for the Ⅰ-Ⅱ mixed mode cracks is established by use of the software ABAQUS. It is employed to calculate the stress intensity factor and strain energy release rate of the Ⅰ-Ⅱ mixed mode cracks. The model results are compared with those calculated by the deduced formula. The error is only 2. 5%, and the rationality of the proposed formula is validated.