单粒磨削过程仿真与工件表面残余应力的离散度分析

Simulation of Single Abrasive Particle Grinding Process and Analysis on the Residual Stresses Scatter

基于有限元软件Deform-2D,建立了具有负前角特征的单颗磨粒磨削热力耦合有限元模型.仿真模拟了磨粒磨削工件时的温度场和应力场分布,分析了工件某点应力在磨削过程中的变化情况及该点最终形成的残余应力.结果表明:随着磨粒负前角的绝对值增加,工件表面残余应力值增大,当磨粒负前角由-15°到-35°时,工件表面残余应力差值达到284 MPa;当磨粒采用负前角为-15°、-25°和-35°时,工件表面产生的残余应力标准差达到145.76 MPa.该研究证明了磨粒几何角度的随机性或离散性是影响磨削工件表面残余应力离散度的重要原因.

A coupled thermal-mechanical model was established for the grinding process of a single abrasive characteristic with negative rake angle based on the Deform-2D FEM software. The temperature and stress distribution were demonstrated, the stress history of one point in the machined workpiece was simulated, and the residual stress generation was analyzed by the single-abrasive grinding process simulation. The results indicate that the workpiece＇s residual stress increases with the negative rake angle absolute value. The workpiece＇s residual stress variation arrives at 284 MPa when the negative rake angle value of an abrasive particle varies from -15° to -35°. The standard deviation is 145.76 MPa when the negative rake angle adopts -15°, -25° and -35° respectively. It validates that the abrasive geometry randomness is an important factor to determine the workpiece residual stress scatter during the grinding process.