Dynamic modelling of the cusp error reduction phenomenon in high speed micro/meso-scale milling processes with ultrasonic vibration assistance

A simulation methodology is proposed to understand and illustrate the surface quality improvement phenomena in precision micro/meso scale milling processes with ultrasonic vibration-assistance as well as the influence of the motion parameters on the topography of the generated surfaces. In the simulation of the machined surface generation process, the trochoidal cutting edge motion is dynamically tracked considering the feed per tooth, cutter runout, deflection, and ultrasonic vibration assistance. The feed per tooth influences the interval between consecutive cutting edge positions on the machined surface, which results in cusps. In addition to this, the cusp geometry is altered by cutter deflection and runout. The machined surface topography can be simulated from the continuous cutting edge motions with and without ultrasonic vibration-assistance. The ultrasonic vibration motion enables an overlap between successive cutting trajectories leading to their intrusion into the previously generated cusp. This leads to an array of possible surface topographies and better surface roughness.