平面磨削条件下温度阈值对残余应力形成的影响

Influence of plane grinding temperature threshold on formation of residual stress

考虑平面磨削条件下的热力耦合作用,研究磨削温度阈值对残余应力形成的影响。基于热弹塑性理论,构建预测磨削热产生残余应力的计算模型;加载椭圆移动热源,使用COMSOL有限元软件进行热-弹塑性多物理场耦合计算,得到磨削区域温度场分布与不同磨削参数对工件表层产生初始塑性应变的影响,从而定量分析磨削温度与磨削残余应力间的相互关系;通过平面磨削实验测得磨削工件表面温度场及磨削后工件表层残余应力,并与数值计算结果进行对比分析。研究结果表明:磨削温度计算值与实测值相对误差在5%以内;磨削温度产生的初始塑性应变对最终残余应力场有较大影响;在一定磨削参数下,可以确定形成初始热塑性应变及残余拉应力的磨削温度阈值。

With consideration of the thermo-mechanical coupling under the condition of plane grinding,the effect of grinding temperature threshold on the formation of residual stress was studied.Based on the thermo-elastoplasticity theory,a calculation model for predicting the residual stress generated by grinding heat was constructed.The elliptical moving heat source was loaded,and the thermo-mechanical multiphysics coupling calculation was performed using COMSOL finite element software.The temperature field distribution in the grinding region and the influence of the parameters on the initial plastic strain of the workpiece surface was obtained,and the relationship between the grinding temperature and the residual stress of grinding was quantitatively analyzed.The surface temperature field of the workpiece and the residual stress of the workpiece surface after grinding were measured by plane grinding experiment,and they were compared with the numerical calculation results.The results show that the error between the calculated and measured values of the grinding temperature is less than 5%,and the initial plastic strain generated by the grinding temperature has great influence on the final residual stress field.With certain grinding parameters,the grinding temperature threshold for initial thermoplasticity strain and residual tensile stress can be determined.