电火花加工表面喷丸残余应力场的有限元分析

Finite element analysis of shot peening residual stress field with EDM surface

喷丸强化作为表面改性技术,对增强工件实际应用,提高使用寿命具有重要意义。采用ABAQUS有限元软件,对电火花单脉冲放电和喷丸强化,在GH3039高温合金材料表层产生的残余应力场进行有限元分析,获得残余应力场的分布规律及残余应力沿层深方向上的变化规律,对电火花单脉冲放电一个脉冲周期后和喷丸强化后工件表面应力分布进行仿真分析。结果表明:电火花加工表面喷丸强化后的残余应力分布规律与理想表面喷丸相同,经喷丸强化后,工件表面残余拉应力明显降低,表层残余压应力有大幅提升,强化效果显著,表面对称轴处径向残余应力比喷丸前降低79.406%,最大径向残余压应力比喷丸前提高了339.143%。

This paper is driven by the insight that shot peening strengthening,a surface modification technology,is of importance to enhancing the practical application of work piece and improving service life.The paper describes the use of ABAQUS finite element software for the finite element analysis of residual stress field generated by the electric spark of single pulse discharge and shot peening in the GH3039 high temperature alloy material surface,the investigation into the law governing the distribution of residual stress field and its change rule along the depth direction,and the simulation analysis of the stress distribution of the workpiece surface subjected to a cycle of discharge of the single-pulse electric spark and shot peening.The results show that the law underlying the distribution of residual stress occurring on the electric spark machining surface treated by shot peening is consistent with that of the ideal surface treated by shot peening; shot peening is capable of such remarkable strengthening effects as a significant decrease in residual tensile stress occurring on a workpiece surface,a significant increase in residual compressive stress,a 79.406％-decrease in the surface along the symmetrical axis radial residual stress,and a 339.143％-improvement in the maximum radial residual stress.