Finite element analysis of laser shock peening induced near-surface deformation in engineering metals

Abstract This paper investigates near-surface residual stress and equivalent plastic strain distributions using finite element method for further understanding of laser shock peening induced plastic deformation. The results indicate that residual stress and equivalent plastic strain at the topmost surface are sensitive to mesh size while they can be well predicted in the subsurface layer. Increasing laser spot size or overlapping rate deepens the compressive residual stress layer while reducing laser spot size leads to uniformly distributed residual stress and equivalent plastic strain. A minimum overlapping rate of 62.5% is necessary to create fully covered compressive residual stress on the target surface using round laser spot. Higher strain hardening exponent results in higher maximum compressive stress and equivalent plastic strain, deeper compressive residual stress and plastic deformation. In addition, higher elastic modulus results in lower equivalent plastic strain and shallower plastic deformation depth.