最大主应力与形状改变比能对断裂的影响

The Influence of the Maximum Principal Stress and Distortion Energy Density on Fracture

分析了裂纹尖端附近的形状改变能密度场和主应力场，结合试验数据研究了最大拉应力与形状改变比能对脆性断裂及断裂方向的影响。认为复合型裂纹的脆性开裂方向主要受形状改变比能的影响，开裂方向靠近形状改变比能取最小的方位，而此处的最大拉应力是影响裂纹开裂的主要因素。

Based on the experimental result, the influence of the maximum tensile stress and distortion energy density on brittle fracture and crack opening direction is analyzed by means of studying the field of distortion energy density and principal stress in the vicinity of a crack tip. The authors hold that distortion energy density has a main effect on the crack opening direction of the brittle fracture of mixed mode crack, which is along the line of maximum distortion energy density, and that maximum tensile stress in the direction is the main factor of influencing crack opening.