A finite-element-analysis of orthogonal metal cutting processes

A 2-D finite-element-model for simulation of the chip formation process in metal cutting is presented. In order to consider the reciprocal interaction between mechanical and thermal loads during cutting a coupled-filed finite-element-analysis is carried out. The complex flow behavior of workpiece material which depends on local strain, strain rate and temperature is described by a thermo-viscoplastic workpiece model. The different frictional behavior in sticking and sliding regions is expressed by a nonlinear stress relationship between normal and frictional stresses at the tool-chip interface. To analyze the large deformation in the cutting zone more accurately a new technique of dynamic remeshing is developed. As the employed general purpose FEM-software ANSYS does not support this feature, an additional preprocessor is developed and integrated into the program. With the aid of this remeshing technique the chip formation process can be simulated more closely to reality, i.e. the modeled tool is not assumed to be ideal sharp, but possesses nose radius and chip breaker. Simulations are carried out for conventional cutting conditions and the effects of cutting conditions, tool geometry and wear progress are examined. Furthermore, the segmented chip formation process during high speed cutting and/or during machining of hardened steel is also analyzed.