Materials Science Forum, Vol.524-525, 135-140, 2006
Dynamic analysis of residual stress introduced by laser peening
Residual stress induced by laser single pulse irradiation was analyzed using a dynamic finite element code, ABAQUS/Explicit. The effects of the magnitude and length of a surface pressure pulse having a circular top-hat shape on the final residual stress in Ti-6Al-4V were investigated. A high peak pressure and/or a long pulse duration was effective in generating large compressive residual stress deep beneath the surface. However, large tensile residual stress features occurred near the centre and edge of the laser spot on the surface for high pressure and/or long pulse durations due to a radial focusing effect. Use of shorter pulse durations avoided this. The peak pressure (3 GPa) required to induce a surface compressive residual stress across the whole area of the spot was slightly higher than the threshold pressure needed to plastically deform the surface.