Modifying Residual Stresses Occurring under Laser Shock Processing through the Generation of Preliminary Stresses

A finite element model has been developed, in which in the course of laser shock processing an elastic preliminary stress is generated in the material. The results are compared with the experimental results, which shows their satisfactory convergence. It is shown that there is a linear relationship between preliminary stresses and compressive residual stresses in the case when the final compressive residual stresses are in the range of [–20%, –100%] with respect to the yield strength. It has been established that the presence of preliminary tensile stresses in the material leads to a higher value of the final compressive residual stresses and the penetration depths thereof.