Dynamic milling force model for a milling cutter under vibration

Abstract

Dynamic milling force under milling vibration is an important indicator for evaluating the milling stability of a milling cutter. The existing modeling methods for milling force ignore the milling vibration for the instantaneous milling behavior of a milling cutter and its teeth, the instantaneous cutter-workpiece engagement, and the milling force. The dynamic characteristics of the milling force need to be revealed. According to the influence characteristics of milling vibration on instantaneous cutter-workpiece engagement, a method for calculating the instantaneous milling attitude angle and the milling motion trajectory of a milling cutter and its cutter teeth was proposed that revealed the changing characteristics of the instantaneous milling behavior of the cutter teeth. The differential element method was used to characterize the distribution state of the milling force of a cutter tooth. The method for calculating the cutting layer thickness of the milling differential element and the instantaneous cutting boundary of the milling edge was put forward, and the instantaneous milling force model of the milling edge was established. By constructing an instantaneous milling force system for multi-tooth milling, a method for calculating the position vector relation variable and the force vector relation variable of the instantaneous milling force of adjacent cutter teeth was proposed, thus revealing the dynamic characteristics of the instantaneous milling force relationship of the adjacent cutter teeth. The dynamic characteristics and the response characteristics of the milling force were tested. The results showed that the calculated results of the dynamic milling force change characteristics of the milling cutter were quite similar to the experimental results. The influence mechanisms of milling vibration, cutter structure parameters, and milling parameters on the dynamic milling force of a milling cutter can be identified with the use of the above models and methods.