基于统一强度理论的断裂准则

基于统一强度理论,在小范围屈服条件下,推导Ⅰ、Ⅱ复合型裂纹裂尖塑性区范围的统一解析解。给出不同拉压比α、泊松比υ、中间主应力影响参数b以及裂纹倾角β下的一族塑性区形状与大小的轨迹,讨论以上参数对裂尖塑性区变化的影响。最后基于裂纹尖端塑性区的解析解,提出了一种复合型裂纹断裂准则,分析了裂纹倾角与初始断裂角的关系。结果表明,该准则预测结果比其它准则更精确,与试验结果吻合得非常好。

A Fracture Criterion Based on Unified Strength Theory

Based on unified strength theory, the unified analytical solutions to the shapes and sizes of Ⅰ,Ⅱ mixed mode crack tip plastic zone under small scale yielding are derived. Then a set of loci for crack tip plastic zone under different material parameters ： The ratio of tension strength to compressive strengtha, poisson＇ s ratiov, material constant b and crack inclination angle βare obtained. Furthermore the influences of the material parameters to the shapes and sizes of crack tip plastic zone are discussed essentially. Finally based on the analytical solutions to the mixed mode crack tip plastic zone, bring forward a mixed mode fracture criterion, the relation between crack inclination angle and crack initiation angle is analysed, the calculation results of this criterion are shown to be better in agreement with experimental data than other criterions.