单丸粒喷丸模型和多丸粒喷丸模型的有限元模拟

采用有限元法模拟喷丸过程，通过比较单丸粒模型和多丸粒模型，研究了喷丸覆盖率对残余应力和材料强化的影响．单丸粒多次冲击模型的模拟结果表明，冲击次数对残余应力幅值影响小，但等效塑性应变明显增加，由此可反映喷丸过程中材料的强化；多丸粒模型的模拟结果表明，当喷丸覆盖率为100％时，残余压应力幅值明显增加，塑性应变与单丸粒一次冲击结果相近．不锈钢喷丸试验结果表明，这两种模型的综合可较好地反映喷丸残余应力的形成和表层材料的强化．

Finite Element Analysis for Shot-Peening Models of Single Shot Impact and Multiple Impingement

The influence of coverage ratio on the residual stress and mechanical properties of a material is investigated by the finite element simulations of the shot-peening models of single shot impact and multiple impingement. For the single shot impact model, the equivalent plastic strain increases with the peening frequency, but the residual stress is not significantly affected by the frequency, and therefore the material is strengthened by the peening frequency. For the multiple impingement model, the residual stress amplitude increases as the 100% coverage ratio is taken into account, and the equivalent plastic strain is similar with that in the single shot impact simulation. The experimental results of a stainless steel demonstrate that the combination of the two models is suitable for analyzing shot-peening process.