INVESTIGATION OF RESIDUAL STRESS FIELD IN THE CURVED SURFACE OF ROUND ROD SUBJECTED TO MULTIPLE LASER SHOCK PEENING

摘要

Laser shock peening (LSP) was employed to squeeze compressive residual stress (CRS) into the curved surface of the round rod with diameter of 16 mm. The residual stress field was induced by nine laser shots irradiating at different locations along the specified path. The developing process of the residual stress field was investigated with finite element analysis, and the corresponding experiments were also carried out to validate the calculated results. Results demonstrate that multiple LSP with 50% overlapping rate can result in residual stress field with the maximum CRS varying from 155.2 MPa to 198.8 MPa along the direction of the rod axis. The peened surface appears wavy in shape and the maximum depth of plastic deformation in the curved surface is 13.41 mu m. The value of surface roughness increases from 3.87 mu m to 4.65 mu m.