Laser Shock Peening: Performance and Process Simulation

For a thick alloy component, LSP can be performed individually or simultaneously on any part of a surface. However, for a thin section, a laser pulse must be split, impacting simultaneously on opposite sides of the section and balancing impact forces. If the section subjected to one-sided LSP is thin enough, the peened spot can create a dimple on the irradiated side and a bulge on the opposite side. It can also cause spalling and fracture if the shock waves are strong enough. Meanwhile, if the laser pulse impacts on a large area, significant curvature or other distortion can be induced in the thin section (Clauer and Lahrman, 2001).
In military aircraft and spacecraft there are a large number of thin metal components that can be treated using two-sided LSP. The aim in this chapter is to provide a better understanding of LSP mechanisms in thin metal sections undergoing two-sided LSP using dynamic finite element (FE) simulations. The distribution of residual stress on the surface and in the interior of thin sections is simulated and mechanically affected critical areas through the thin sections are carefully evaluated. The results are correlated with the experimental data available in literature. The studies are also focused on obtaining a better understanding of two-sided LSP in relation to effects of some essential factors on the residual stress field, such as laser spot size, pressure, material geometry and number of LSP impacts.
Clauer and Lahrman (2001) investigated the compressive...