Stability analysis of a spline-rotor system subjected to friction-induced self-excited vibrations

Spline joints introduce cross-coupling, internal friction, and interface discontinuities, that can lead to system instability and self-excited vibrations under certain operating conditions. Predicting the onset conditions and amplitudes of self-excited vibrations in the spline-rotor system, as well as their dependence on physical parameters such as misalignment and interfacial friction, is crucial for effective design work. Therefore, in this study, a comprehensive stability analysis of a spline-rotor system subjected to self-excited vibrations induced by interfacial friction is carried out. First, the complex eigenvalue method is used to identify the equilibrium point stability. Then, numerical continuation methods are applied to perform a global stability assessment and to rapidly predict limit cycles. To improve computational efficiency, model reduction is integrated, which allows a systematic investigation of the effects of parameters on system stability and vibration response, elucidating the friction mechanism and influence laws. Through this in-depth study, the stability and nonlinear behavior of the spline rotor system subjected to self-excited vibration is revealed, providing crucial theoretical support for effective design strategies to mitigate system instability and self-excited vibration in rotating machinery.