Abstract: Based on experimental observation and theoretical analysis this paper suggests that there are three important characteristics in the initiation process of subsurface crack during rolling contact: (1) the randomness of initiation angle; (2) the mechanical factors of the initiation and propagation are independent of each other and can be separated; (3) the statistical characteristic of initiation depth. The depth where the subsurface crack initiated accords statistically with the depth of maximum alternating shear stress. A dislocation releasing model is proposed to explain the phenomenon observed during the test.

Key words: 滚动接触, 接触疲劳, 裂纹萌生