Numerical simulation of surface deformation and residual stresses fields in laser shock processing experiments

Laser shock processing (LSP) has been proposed as a competitive alternative technology to classical surface treatments for improving fatigue, corrosion and wear resistance of metals, and has recently been developed as a practical process amenable to production engineering. Although valuable experimental work has been performed exploring the capability of the technique to provide enhanced mechanical properties, an important lack of work exists on the theoretical predictive assessment of the required process parameters. In this paper, a model is presented able to provide a predictive estimation of the residual stresses and surface deformation induced by laser action relevant for the analysis the influence of the different parameter in the process. Special emphasis will be posed on the part of the model devoted to the analysis of the solid material mechanical behaviour under the surface pressure pulse exerted by the expansion of the laser generated plasma. With the aid of the model, the influence of pulse duration, pulse pressure peak, spot radius, number of shots, overlapped shots and material properties have been analyzed. The great influence of 3D deformation effects in the process is clearly shown as one of the most important limiting factors of the process traditionally neglected in previous literature. (C) 2004 Elsevier B.V. All rights reserved.