J. Phys. IV France 01 (1991) C3-487-C3-494
RESIDUAL STRESSES INDUCED BY LASER-SHOCKSP. BALLARD1, J. FOURNIER, R. FABBRO2 and J. FRELAT1
1 Laboratoire de Mécanique des Solides, Ecole Polytechnique, F-91128 Palaiseau cedex, France
2 Laboratoire d'Application des Lasers de Puissance, ETCA, 16, av. Prieur de la Côte d'or, F-94114 Arcueil, France
When irradiating a metallic target with a short and intense laser pulse, a high pressure plasma is produced on the surface. An elastic-plastic wave is, then, propagating in the target, creating plastic strains. As a result, a residual stress field is induced. In this paper, by mean of a very simple model, we evaluate the laser produced plasma pressure. The analysis of the resulting wave propagation allows us to compute the plastic strain field. Using these results, we express analytically the induced surface residual stress and the plastically affected depth. We show how this work allows the optimization of the use of laser-shocks as a fatigue surface treatment and an example of application is presented.
© EDP Sciences 1991