Dynamic Analyses and Design Optimization of High-Speed Spindle-Bearing System

High-Speed Machining(HSM) is widely used in the manufacturing industry. However premature failure without alarming signs leads the development of spindle technology to be strategically critical for the HSM implementation. This paper presents a software package using Matlab for dynamic modelling and simulation of HSM spindle. It has been developed for industrial use and is composed of several modules. First a design module allows elaborating a Finite Element Model(FEM) on the basis of a dedicated rotor-beam element. A readjustment module allows tuning specific material properties such as Young modulus, shear modulus and damping coefficients in order to fit model results to the experimental frequency response function. A simulation package allows to perform dynamic analyses such as transient analyses, mass unbalance analyses and synchronous excitation analyses representative of the milling tool teeth impact. Specific dynamic effects that are underestimated in previous studies are highlighted. Spindle dynamics properties are shown to be strongly dependent on rotation frequency and have to be evaluated for accurate stability prediction. Finally, optimization studies are performed on spindle design and on cutting condition by integrating the predicted FRF of the spindle to the Budak—Altintas chatter stability approach.