Research On Nanometric Cutting Process Of Monocrystal Copper Based On Quasicontinuum Simulation

As the development of ultraprecision and nano-machining technology, throughsingle point diamond turning/grinding and some other ways, it’s now possible toremove very thin chips at the nanoscale. But the chip-removing andsurface-generating mechanism are significantly different form traditional cuttingprocesses because of the influence of surface effect and scale effect. As a result, usingtraditional macro continuum mechanics methods, such as the finite element theory toexplain nanometric cutting mechanism may cause significant error. Meanwhile, themolecular dynamics method is restricted to the computer hardware and the workpiecesizes are rather small ranging from nanometers to decade nanometers. Consequently,multiscale modeling is much needed to enlarge the simulation scale whilemaintaining the computational resolution.Quasicontinuum method (QC) is one of the coupled atomic/continuummultiscale analysis methods which has a relatively longer history and larger influenceon the multiscale numerical simulation for deformation and failure of materials. So,Quasicontinuum method is used to study the nanometric cutting process ofmonocrystal copper in this paper.Firstly, the development and application of multiscale methods of the presentsituation are introduced and Quasicontinuum method is compared with FiniteElement Method (FEM) and Molecular Dynamics (MD).Then, the multiscalesimulation modle is established based on Quasicontinuum method through studyingits basic principles and modeling techniques.Secondly, the multiscale modle is used to study the material removing and chipformation mechanism. Due to the fact that QC has the advantage of both FEM andMD, we can better understand the nanometric cutting mechanism from many aspectssuch as the stress cloud chart as well as the atomic bitmap.Thirdly, the effect of depth of cutting、orientation of workpiece and tool geometry parameters (tool rake angle、tool clearance angle and tool edge radius) onthe nanometric cutting process of monocrystal copper is studied. Based on multiscalesimulation, the different stress and deformation condition as well as the parameters’influence on the cutting forces and strain energy are analyzed.