THE TECHNIQUE FOR RETARDING SURFACE CRACK
表面裂纹疲劳止裂技术

Fatigue experiments of surface crack with wedge and without wedge subjected to low freqency tension and high frequency bending have been performed. The results show that crack arresting technology of "artificial wedge" has remakable effect on suface cracks.The growth law of wedged cracks is consistent with the non-wedged cracks. In tension condition, the retardation effect of direction a and c is almost the same.The development laws of surface crack aspects with wedge and without wedge are similar. But in bending condition, the retardation effect of direction a is greater than that of direction c, and the aspect ratios of wedged cracks and non-wedged cracks are not consistent. It has been found that retardating effects are mainly in the early stage of adding wedge. Under tension condition, an emperical formula of crack aspect of surface crack fatigue test is proposed.