基于光滑粒子流体动力学的紫铜切屑形态研究

Study on Chip Morphology of Red Copper Based on Smoothed Particle Hydrodynamics

FEM存在网格变形和重构等诸多问题,难以解决切削过程中刀具前端材料出现的极端塑性变形以及高应变率问题。而无网格光滑粒子流体动力学方法能够解决FEM中由于网格变形所引起的畸变问题,从而模拟出各种材料的任意变形。目前针对SPH方法的切削仿真研究主要集中于工艺参数、材料本构等外部参数的敏感性分析,而对于SPH公式的选择、粒子密度等内部参数的敏感性分析较少。为此,本文通过使用Ls-Dyna仿真软件构建了基于SPH的紫铜正交切削仿真模型,并搭建了正交切削实验平台。针对显著影响紫铜切屑形态及计算精度的内部参数进行了研究,并与切削实验的切屑形态及切削力进行对比,结合仿真计算时间成本,最终确定粒子密度为216000pcs/mm^(3)的重整化SPH更适合紫铜切削仿真实验研究。

The Finite Element Method(FEM)is widely used in numerical simulation to study the cutting mechanism.FEM has many problems,such as mesh deformation and reconstruction.It is difficult to solve the distortion problems of extreme plastic deformation and high strain rate of the material during the cutting process.The meshless Smoothed Particle Hydrodynamics(SPH)method can solve the problems caused by mesh deformation in FEM,so that it can simulate the arbitrary deformation of various materials.At present,the cutting simulation research of the SPH method mainly focuses on the sensitivity analysis of external parameters such as process parameters and material constitutive model parameters.However,there is less sensitivity analysis on the selection of the SPH formula,particle density,and other internal parameters.In this paper,the simulation model of orthogonal cutting of red copper based on SPH is built by using Ls-Dyna simulation software.The orthogonal cutting experimental platform is also being built.The internal parameters that significantly affect the chip morphology and calculation accuracy of red copper are studied.Through the comparative study with the chip shape and cutting force of cutting experiment,combined with the cost of simulation calculation time,it is finally determined that the renormalized SPH with particle density of 216000pcs/mm^(3)is more suitable for the simulation experiment of red copper cutting.