Numerical Simulation of Surface Residual Stress and Deformation of FGH95 Alloy Under Multiple Laser Shock Peening with Square Spots

A modified finite element simulation method was used to predict the surface residual stress and surface deformation of FGH95 Alloy under multiple Laser Shock Peening (LSP) with square spots. By comparing the target surface residual stress distribution under different spot overlapping percentage, the 50% spot overlapping percentage was determined. On this basis, the effects of different shock times and peak shock pressure on surface residual stress and deformation were analyzed. The numerical simulation results show that the surface residual stress and surface deformation increase with the increase of laser shock times, and the corresponding residual compressive stress ranges under different shock times are −700.1 MPa, −790.5 MPa and −795.3 MPa, respectively. The corresponding surface deformation amplitudes are −5.58 × 10−4 mm, −6.64 × 10−4 mm and −7.01 × 10−4 mm, respectively. After two laser shocks, the surface residual stress and surface deformation tend to be saturated. With the increase of shock wave pressures, surface residual stress and surface deformation increase, and the corresponding residual compressive stress ranges under different shock wave pressures are −497.3 MPa, −700.1 MPa and −934.5 MPa, respectively. The surface deformation amplitudes are −2.84 × 10−4 mm, −5.58 × 10−4 mm and −10.4 × 10−4 mm, respectively.