Abstract
A research program for investigating the thermo-elasto-plastic behavior when a laser beam is irradiated to the surface of a thin metal plate with cooling its backside is described in this paper. The residual deformation and the residual internal force occur in a thin plate after the cooling process. Therefore the plastic analyses after the second irradiation are more complicated. In this analysis, the deformation increments can be decomposed into an elastic component and plasticity component on the interaction curve basing on the radial flow rule. In this paper, the plastic analysis for the fifth irradiation, which is obtained after the re-yielding of the fourth irradiation were carried out. Especially, the distributions of the residual internal force obtained after cooling process for the fifth irradiation are compared with fourth irradiation.