基于裂尖塑性区的复合材料复合型裂纹断裂准则

Fracture criterion for mixed mode crack of composites based on the crack tip plastic zone

基于Tsai-Hill强度理论,在平面应力条件下,推导了复合材料Ⅰ/Ⅱ复合型裂纹塑性区尺寸表达式,分析了裂纹扩展方向与裂纹尖端塑性区的关系,推广并证明了R准则在复合材料裂纹扩展方向预测中的适用性。数值算例分析了不同纤维方向和裂纹倾斜角对复合材料复合型裂纹开裂角的影响。结果表明,R准则是一个通用的断裂准则,适用于预测各向同性材料和复合材料各种裂纹的扩展方向;纤维方向和裂纹倾斜角对断裂角的影响较明显,可能是导致复合材料复杂断裂机理的原因之一。

Based on Tsai-Hill failure criterion, the crack tip plastic zone size expression of mixed mode Ⅰ / Ⅱ for composites was derived under plane stress condition. The relation between crack tip plastic zone and the direction of crack growth was analyzed, and the applicability of R criterion for forecasting the crack growth direction of composites was validated. The influence of different fiber orientation and crack inclination on the direction of crack growth was analyzed by the numerical example. The result indicates that R criterion is a universal criterion and applicable for forecasting the crack growth direction of isotropic materials and composites;the influence of different fiber orientation and crack inclination on the direction of crack growth is obvious, and it may be one of the reasons for complicated fracture mechanism of composites.