超声振动珩磨表面残余应力数值模拟研究

发布时间：2018-05-27 05:22

本文选题：超声振动 + 珩磨　；参考：《表面技术》2015年07期

【摘要】：目的磨削产生的残余应力对工件表面特性有重要影响,超声振动珩磨使磨粒具有极大的加速度而改变了材料去除机理,研究超声振动对工件表面残余应力的影响及产生机理。方法分析残余应力形成有限元理论,建立基于热弹塑性有限元法的超声振动单颗CBN磨粒切削40Cr Ni Mo A热力耦合有限元模型,并设置两次切削、卸载、约束转换及冷却等分析步。通过数值模拟得到不同振动参数下表面残余应力的分布情况,并对模拟结果进行分析。结果有限元计算得到的各分析阶段应力分布存在差别,超声振动参数设置达到仿真要求;对磨粒施加超声振动后珩磨力下降约26%,珩磨热降低约17%,切向残余压应力有所减小,垂直珩磨速度方向拉应力减小并向压应力转变。结论超声振动使珩磨力和珩磨热有一定程度降低从而改变了残余应力的分布及数值;振动频率在20 k Hz波动时对残余应力的影响不大;磨削速度减小,切向残余压应力增大,垂直磨削方向残余拉应力减小;振幅增大时,切向残余压应力减小,垂直方向残余应力增大。
[Abstract]:Objective the residual stress produced by grinding has an important effect on the surface characteristics of workpiece. Ultrasonic vibration honing makes the abrasive particles have a great acceleration and changes the material removal mechanism. The influence of ultrasonic vibration on the surface residual stress of workpiece and its producing mechanism are studied. Methods the finite element theory of residual stress formation was analyzed, and the 40Cr Ni Mo A thermo-mechanical coupled finite element model of ultrasonic vibration single CBN abrasive cutting was established based on thermoelastic-plastic finite element method. The distribution of surface residual stress under different vibration parameters is obtained by numerical simulation, and the simulation results are analyzed. Results there are differences in stress distribution in each analysis stage obtained by finite element calculation, the setting of ultrasonic vibration parameters meets the requirements of simulation, the honing force decreases by about 26%, the honing heat decreases about 17%, and the tangential residual compressive stress decreases after applying ultrasonic vibration to the abrasive particles. The tensile stress in the vertical honing speed direction decreases and changes to the compressive stress. Conclusion Ultrasonic vibration reduces the honing force and honing heat to a certain extent, thus changing the distribution and value of residual stress, the vibration frequency fluctuating at 20 kHz has little effect on the residual stress, and the grinding speed decreases and the tangential residual compressive stress increases. The residual tensile stress in the vertical grinding direction decreases, and the residual compressive stress in the tangential direction decreases and the residual stress in the vertical direction increases when the amplitude increases.
【作者单位】：西南石油大学机电工程学院;
【基金】：四川省教育厅自然科学基金重点项目(13ZA0178)~~
【分类号】：TG580.6

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