Finite element simulation of chip formation in orthogonal metal cutting

A coupled thermo-mechanical model of plane-strain orthogonal metal cutting with continuous chip formation is presented using the commercial implicit finite element code MARC. The flow stress of the work-material is taken as a function of strain, strain-rate and temperature in order to take into account the effect of the large strain, strain-rate and temperature associated with cutting on the material properties. The cutting process is simulated from the initial to the steady-state of cutting force, by incrementally advancing the cutting tool, while a geometrical chip-separation criterion, based on a critical distance at the tool tip regime, is implemented into the MARC code by employing the rezoning procedure. The shape of the chip and the stress, strain and strain-rate distributions in the chip and workpiece, as well as the temperature fields in the workpiece, chip and tool, are determined. The calculated cutting forces are compared with published experimental data and found to be in good agreement, validating, therefore, the proposed FE model.