喷丸过程中的能量转化及残余应力分布研究

本文建立了喷丸表面强化过程的三维有限元模型，研究了靶材的力学性能及弹丸喷射速度对能量转化率和残余应力分布的影响规律。通过对有限元计算结果的分析发现，杨氏模量与屈服强度之比E/&;#61555;y较大，应变硬化率较低的靶材喷丸效率较高。屈服强度的提高使得最大残余压应力变大，残余压应力场深度变小。应变硬化率和喷丸速度的提高均会使最大残余压应力及其深度变大，同时会使表面残余压应力减小并向拉应力转变。本文的研究结果从能量转化的角度为喷丸强化件材料的选择提供了理论基础

Energy conversion and residual stress distribution in shot peening process

Three-dimensional FE model of the shot peening process was developed in the present study to investigate the effects of mechanical properties of the target and the impact velocity on energy transformation coefficient K as well as residual stress distribution. The FE results show that the target with a higher ratio of E/y and a lower strain hardening rate exhibits a high efficiency of shot peening. The increase of yield stress of the target can induce an increase of maximum residual compression stress, while a decreased depth of the residual stress filed can be observed. Both of the increases of strain hardening rate and impact velocity can induce increases of maximum residual compression stress as well as depth of residual compression stress field, meanwhile, it could also cause the surface residual compression stress to decrease. The result of the present study provides a theoretical foundation for the selection of target material in view of energy transformation