关键词: 激光冲击波；裂纹；应力强度因子；扩展速度

Abstract:

The relationship of the tip of the crack dynamic stress intensity factor and the velocity of the crack propagation in the metal sheet and laser shock parameters were investigated. A new mode of the tip of the crack was put forth by the theory of fracture dynamics, and then the dynamic stress intensity factor of the crack under the laser shock wave was also obtained. And superposition method was adopted to add dynamic stress intensity factor arisen by the external load and dynamic stress intensity factor arisen by the remains residual stresses. Transformation on the characteristics of aerial alloy Ti6Al4V by laser shock processing and influence on the fatigue life with these transformations were studied.The influence of surface residual stress by laser shock processing and the outer load on crack propagation velocity was discussed. Utilizing these solutions the crack initiation life were developed to evaluate exactitude.

Key words: laser shock wave;surface crack;dynamic stress intensity factor;propagation velocity