基于SPH方法单颗粒磨削TC4动态过程模拟研究

Dynamic Simulation of Single Abrasive Grain Cutting TC4 Based on SPH Method

考虑到FEM(Finite Element Method)进行切削仿真时会因网格畸变而影响计算精度,因此采用新型光滑流体粒子动力学(SPH,Smoothed Particle Hydrodynamics)无网格法对单颗CBN(Cubic Boron Nitride)磨粒磨削钛合金TC4的过程进行三维数值仿真。通过建立与真实磨粒相似、刃部有一定圆弧半径的磨粒FEM模型及钛合金工件的SPH模型,研究了磨粒切削深度对磨削力及磨屑形成过程的影响。分析结果表明:磨削力随着磨粒切削深度的增大而增大,磨削力比则随着切削深度的增大而减小;当磨粒速度一定时,TC4工件的磨屑形成情况与切削深度存在重要关系。仿真结果与理论分析吻合较好,验证了SPH方法模拟单颗粒磨削钛合金材料的可行性。

Considering the negative effects of mesh distortion on calculation accuracy in FEM simulation, a novel mesh free method named Smoothed Particle Hydrodynamics(SPH) method was employed to simulate the process of single CBN abrasive grain cutting TC4. Establishing a SPH model of TC4 workpiece and a FEM model of single abrasive grain with cutting edges similar to the real abrasive grain, the influences of cutting depth on grinding forces and chip formative process were studied systematically. The simulation results state that grinding forces enlarge with the increase of cutting depth, while grinding force ratio decreases. And TC4 chip formative process is also closely related with cutting depth. The simulation results have little error compared with theoretical analysis, verifying the feasibility of applying SPH method to simulate the cutting process of titanium alloy.