The experimental study on interaction of vibration and dynamic force in precision milling process

Milling is usually a high-quality and high-efficient processing method for the machining of large structural parts of aerospace equipment. However, the coupled vibration produced by the interaction between the machining process and the dynamic load of the machine tool causes relative displacement of tool and workpiece, which makes it hard to precisely control the dimensional accuracy of the parts. In this study, the coupling vibration of cutter and workpiece under the interaction of machine tool and process dynamic load during the milling of Al 7075-T651 is investigated. The dynamic characteristics of the machine structure and the cutting process are taken into account, and the causes of coupling vibration are analyzed. A novel vibration prediction model is presented by investigating the dynamics between the milling excitation force and the response of the machine tool through the interaction analysis theory. The wavelet packet transform and the frequency response function are utilized to decouple the interaction between the dynamic force load and the vibration response. The predicted X- and Y-direction vibrations from spindle and workpiece are obtained by the proposed method, and the results show that the root-mean-square errors of these vibrations are controlled at around 20.8%, 21.8%, 17.4%, and 17.6%, respectively. The favorable prediction performance of the vibration model indicates that the superimposed coupling of the dynamic milling force and the excitation of the spindle rotation has significant influence on the analysis of machining vibration.