Mechanism of Cutting Force and Surface Generation in Dynamic Milling

TLDR

The study presents an improved milling model that predicts cutting forces and surface finish under rigid or dynamic conditions. The model uses trochoidal cutter motion and kinematic modeling of cutter and workpiece vibrations to determine cutting forces in five distinct regions and compute surface generation. Simulation and experimental results confirm the model, showing that choosing the tooth‑passing frequency as an integer multiple of the dominant tool‑workpiece vibration frequency eliminates vibration imprint on the surface finish.

Abstract

An improved model of the milling process is presented. The model proposes a method of determining cutting forces in five distinct regions where the cutting edge travels during dynamic milling. Trochoidal motion of the milling cutter is used in determining uncut chip thickness. The kinematics of the cutter and workpiece vibrations are modelled, which identifies the orientation and velocity direction of the cutting edge during dynamic cutting. The model allows the prediction of forces and surface finish under rigid or dynamic cutting conditions. The proposed mechanism of chip thickness, force and surface generation is proven with simulation and experimental results. It is found that when the tooth passing frequency is selected to be an integer ratio of a dominant frequency of tool-workpiece structure in milling imprint of vibrations on the surface finish is avoided.