【作者】 任旭东； 张永康； 冯爱新； 张西良；

【Author】 REN Xu-dong ZHANG Yong-kang FENG Ai-xin ZHANG Xi-liang (Jiangsu Key Laboratory of Laser Manufacture Science and Technology Ministry,Jiangsu University,Zhenjiang 212013,China)

【机构】 江苏大学机械学院光子制造科学与技术省重点实验室；

【摘要】 研究了激光冲击加载下链篦机中关键零部件小轴表面残余应力的变化,从断裂力学理论出发,讨论了激光加载产生的残余压应力对材料表面裂纹疲劳寿命的影响,通过推导出的应力影响公式可清楚表明零件实际承受的裂纹尖端应力强度因子幅值的变化受激光冲击诱发的残余压应力值影响,且其应力比大大减小,其结果将使疲劳裂纹扩展门槛值获得提高,在残余压应力场中链篦机中件小轴表面疲劳裂纹的扩展速率明显降低,结果表明残余压应力能有效对金属板材的裂纹起到闭合作用。更多还原

【Abstract】 The effect of the laser shock processing on metal surface residual stress was analyzed.And the influ- ence of the surface residual stress on material fatigue life after laser shock processing was discussed from the theory of the fracture mechanics.A stress formula was set up to indicate the function of the residual stress on fatigue life.It was observed that the dynamic stress intensity factor of the crack and the stress ratio were de- clined due to laser shock processing.This would make the spread doorsill of the fatigue crack increasing.The surface residual stresses play a critical role in the enhancement of fatigue life and closing the surface crack during the process of laser shock processing.更多还原