SPECIAL ISSUE PAPER 1935 Periodicmotions of a dual-disc rotor systemwith rub-impact at fixed limiter

Abstract: Periodic motions of a rotor system with two discs are investigated where rub-impacts occur at fixed limiter for a test rig with dual discs. First, a finite element (FE) model of the rotor system is developed. Then numerical simulations based on the FE model are conducted to study the rotor transverse vibrations of the rotor system under three typical cases with different rotating speeds, rub-impact clearances, rub-impact rod stiffness, and rub frictions. The results are further compared with typical multiperiodic characteristics by experimentally measured vibrations. The simulations demonstrate different rotor motions, including periodic, quasi-periodic or complex characteristics, which coincide with experimental measurements. Finally, the non-stationary time-frequency domain characteristics of rub-impact motions are investigated via the Hilbert– Huang transform, and intrinsic mode functions (IMFs) and instantaneous frequencies of the three typical cases are obtained. The research has revealed some of the inherent vibration features of the dual-disc rotor system with rub-impact only occurring at fixed limiters