Mathematical Model and Quantitative Analysis of Residual Stress Hole During Laser Shock Peening

Laser shock peening (LSP) can induce residual compressive stress on the component surface, thus improving the fatigue life of the component. Therefore, LSP has been extensively employed in aerospace, vehicle engineering, and other industrial fields. To research the influence factors of residual stress hole (RSH) which often occurred in LSP, a “volcano shape” mathematical model was conducted. Indexes for quantitatively describing RSH were proposed, such as relative crater depth, relative crater width, and stress loss ratio. Preliminary analysis based on the experimental study was carried out. The results showed that the relative crater depth is the main impact factor to RSH. Overlapping LSP is suggested to be adopted when the relative crater depth is more than 10%. In addition, the spacing of the adjacent spot centers should be equal to the “crater” radius of RSH so as to get the uniform residual stress under the premise of higher LSP efficiency.