Residual stress field induced by shot peening based on random-shots for 7075 aluminum alloy

High-strength 7075-T651 aluminum alloy was selected as the research object, and the random-shots FE model was developed; the influences of shots number and spatial location on residual stress field (RSF) were discussed; the influence of analysis step time (AST) on the stability of RSF was analyzed, and the influences of coverage rate and surface roughness of component on the distribution of RSF were investigated. The results indicate that the generated RSF is seriously affected by subsequent shots number and location; RSF tends to be stable when AST adds to 0.075 ms for 45 shots FE model, and the AST values of 15, 25, 65 and 85 shots FE model are 0.065, 0.0683, 0.0817 and 0.0883 ms respectively. For shot peening with different coverage rates, σsrs and σmcrs increase with the variation of shots number from 15 to 65, then decrease when shots number is 85, variation of Zm is not obvious, Z0 increases with the increment of shots number. For shot peening of component with different surface roughness Ra, variation of σsrs has no obvious regularity, and σmcrs, Zm and Z0 decrease with the increment of Ra.