MODELING SCHEMES, TRANSIENCY, AND STRAIN MEASUREMENT FOR MICROSCALE LASER SHOCK PEENING

摘要

In this paper, a coupled modeling scheme, that considered the dynamic evolution of laser-induced plasma and the complete physical interaction between plasma, confined medium, coating layer and the peened metal in laser shock peeing (LSP), is compared with two decoupled modeling schemes, in which shock pressure was first determined and used as loading in subsequent FEM based stress/strain analysis. The relative merits and limitations of these schemes are evaluated in terms of their ability to describe process transiency such as shock pressure, shock velocity and dynamic deformation history, and to predict the stress/strain to be imparted into a target material. Both bulk and thin film samples of copper were studied. Model predictions were investigated together with strain measurements based on X-ray micro-diffraction technique.