A new effective method to estimate the effect of laser shock peening

摘要

The paper focuses on the influencing parameters to the plastically affected depth and maximum residual stress of the metallic target after laser shock peening. Firstly, by using a new coupling analysis method, the shock pressure characteristics including peak pressure and pressure duration are given. Secondly, based on the deduced pressure profile, dimensional analysis method is employed to find the controlling parameters, and the relationships of plastically affected depth, maximum residual stress versus peak pressure, pressure duration and laser spot size are given. Thirdly, a two dimension axisymmetric finite element model based on LS-DYNA package is built, and the dynamic responses of metallic target subject to laser shock processing are computed with different input parameters. The result shows that the plastically affected depth is proportional to pressure duration, whereas the maximum residual stress is independent with it; the plastically affected depth and the maximum residual stress are not affected by laser spot size within a certain range, whereas have approximate linear relationships with peak pressure after reaching to a certain level; maximum residual stress and plastically affected depth increase significantly for a thin target configuration in laser shock peening system.