Distribution and Optimization of Residual Stress Fields in Titanium Simulated Blade Treated by Laser Shock Peening

According to the characteristics of mechanical response of titanium alloy, a new constitutive model for ultra-high strain rate deformation in the process of laser shock peening was established. The constitutive model parameters were obtained by the inverse optimization. The propagation characteristic and residual stress-strain distribution under the shock wave were analyzed. The relationship between residual stress and laser power density and laser impacts was indicated via sensitivity analysis of laser parameters. According the above conclusions, the laser shock peening technic on the titanium simulated blades was optimized to obtain the appropriate residual stress distribution. The fatigue test result indicated that the fatigue strength by the optimized technic was improved by 25%, compared to the anterior technic without optimization.