Stability of lateral, torsional and axial vibrations in drilling

Instability caused by whirling, lateral and torsional-axial modes of the drill causes dimensional inaccuracies of the holes and may damage the drills. A generalized stability model for drilling dynamics is presented in this paper. The model considers the regeneration of chip thickness due to the tool deflection in the lateral, torsional and axial directions. The tool wear is considered on damping of high frequency, torsional vibrations during drilling process. The stability for whirling, lateral and torsional axial chatter is predicted simultaneously and analytically in semi-discrete time domain. The stability model is experimentally verified by conducing series of drilling tests with a sharp and worn tool. (C) 2013 Elsevier Ltd. All rights reserved.