A finite element study of the effect of friction in orthogonal metal cutting

Abstract

The process of orthogonal metal cutting is studied with the finite element method under plane strain conditions. A computational procedure has been developed for simulating orthogonal metal cutting using a general-purpose finite element code. The focus of the results presented in this paper is on the effect of friction on thermomechanical quantities in a metal cutting process. A series of finite element simulations have been performed, in which a modified Coulomb friction law is used to model the friction along the tool–chip interface, and a finite element nodal release procedure is adopted to simulate chip separation from the workpiece. A tool rake angle ranging from 15° to 30° and a friction coefficient ranging from 0.0 to 0.6 have been considered in the simulations. The results of these simulations are consistent with experimental observations in the literature. In particular, it is found that shear straining is localized in the primary shear zone while the material near the tool tip undergoes the largest plastic strain rate. However, the maximum temperature rise, which is induced by energy dissipation due to plasticity and friction, occurs along the tool–chip interface, not in the primary shear zone. Furthermore, the maximum temperature, the contact length, the shear angle, and the cutting force are found to depend strongly on the coefficient of friction.