Self-excited vibration suppression of a spline-shafting system using a nonlinear energy sink

The rotating instability and corresponding non-synchronous vibrations seriously affect the long-term operations of modern high-speed rotating machinery. However, there is still a lack of effective control methods to prevent the unstable vibration of the rotor system. This study focuses on the effective suppression of large-amplitude selfexcited vibrations in spline-shafting systems using a nonlinear energy sink (NES). A nonlinear dynamic model for a spline-shafting system incorporating the non-smooth friction interface is developed. The corresponding friction-induced vibration and the instability mechanism are explored through the time-frequency analysis. The NES is then employed for the self-excited vibration suppression and the optimum parameters of the NES are obtained through the rotor vibration response surface. Several numerical analyses are conducted to investigate the suppression performance of the NES under the condition of different load torque. Lastly, the mitigation of the rotor self-excited vibration is realized and the mechanism of NES suppressing self-excited vibration by strong modulated response is elucidated. The obtained results show that the NES can not only effectively reduce the vibration of the rotor system in the vicinity of resonance, but also alleviate the large amplitude of self-excited vibration simultaneously, which may provide helpful guidance for the dynamic design of complex rotor systems.