Finite element simulation of low frequency vibration-assisted drilling with modification of oscillation modes
Lukas Schumski, Tebbe Paulsen, Jens Sölter, Bernhard Karpuschewski
Abstract
Low frequency vibration assisted drilling (LFVAD) is an important cutting process, especially for hard-to-machine materials and materials that tend to produce long chips. In LFVAD the continuous axial tool movement in feed direction is superimposed with a sinusoidal oscillation of the tool. Due to the vibratory movement in axial direction an interrupted cut is enforced leading to the generation of comparatively small chips. In the present study, a chip formation simulation utilizing DEFORM for predicting thrust force and drilling torque was set up aiming at an optimization of LFVAD of the titanium alloy Ti6Al4V by means of modifications of the vibratory tool movement. In order to reduce computation times an initial borehole topography was generated utilizing a kinematic model of the process prior to the chip formation simulation. The simulation results regarding the time-dependent thrust force and drilling torque are compared with measurements. The results show that the modification of the oscillation mode can significantly decrease the maximum thrust force and the torque. Thus the finite element simulation of the process enables a predictive optimization of oscillation modes in LFVAD.