Prediction of Updated Cutting Parameters for a Spindle Subjected to Bearing Wear: A Free Vibration-Based Approach

Abstract

The effects of spindles vibrational behavior on the stability lobes and the chatter behavior of machine tools are discussed. Multi-segment spinning spindle models, developed based on the Euler-Bernoulli beam bending theory, have revealed that the system exhibits coupled Bending-Bending (B-B) vibration and its natural frequencies are found to decrease with increasing spinning speed. It has also been observed from the experimental data that an average spindle goes through three stages of operation, namely settling, normal operation and failure. As spindle fundamental frequency changes, the stability lobes change, i.e., the originally selected cutting parameters could lead to chatter. It is shown that using the experimental results, it is possible to establish an expression for the variation of spindle's fundamental frequency in terms of machine hours, which can in turn be used to predict chatter-free cutting parameters through calibrated models and the stability lobes.