Abstract.

The tool plays an important role in cutting process. The aim of this paper is to investigate
the effect of tool geometrical parameters on the chip formation and cutting force with orthogonal
cutting models. The large deformation Rigid-visco-plastic FEM program DEFORM-2DTM is used, and thermo-mechanical coupling effect are considered. The chip separation from workpiece is implemented by remeshing. Contrary to traditional cutting simulation, the workpiece is moved and the tool is fixed, which is consistent with actual process. The effects of tool rake angle on the chip geometry and cutting force are analyzed. The simulated cutting forces are compared with results in other references. The research results are a help to cutting process study and cutting tool design.

Introduction

Cutting processes, such as turning on lathe, drilling and milling, remove material from surface ofthe workpiece, thereby producing chips. The basic mechanics of chip formation is essentially thesame for all these operations. Although almost all cutting processes are three-dimensional in nature, the two-dimensional model shown in Fig. 1, known as orthogonal cutting, is still useful in studying the basic mechanics of cutting. In this model, the workpiece moves at a certain velocity V and a depth of cut t0. A chip is produced ahead of the tool by shearing the material continuously along the shear plane.

The major independent variables that we can change directly in the cutting process include tool
and workpiece material, tool shape, surface finish and sharpness, cutting conditions, cutting fluid,
machine, etc. They can influence the type of chip produced, force and energy dissipated in the
cutting process, temperature rise in the workpiece, the chip, the tool, wear and failure of the tool,
the surface finish produced on the workpiece after machining, etc. Among these independent
variables, the tool parameters play an important role in cutting processes，and some novel tools can improve the cutting quality. A cutting tool includes some dimensions parameters and angles
parameters, which can be mainly characterized by the rake angle, clearance angle, and cutting edge radius.