Abstract: Both regenerative cutting and mode-coupling principles are taken into consideration to model the delayed dynamics of regenerative machining system under stochastic excitation. The influencing of the orientation of principal stiffness axes on machining instability lobes is analyzed. The dynamic responses of machining system are sampled as the observation data. The cross fourth-order cumulant based ESPRIT approach to jointly estimating harmonic parameters is proposed, which is applied to investigate the influence of the orientation of principal stiffness axes into the harmonic parameters of dynamic response in mode-coupled regenerative machining system. Several novel dependent characteristics of the harmonic parameters on the orientation of principal stiffness axes is disclosed, these harmonic parameters includes the frequency, phase shift and cross power of the dynamic machining responses.

Key words: machine tool; regenerative machining; mode-coupling principle; dynamic stability; cross high-order cumulants.