Characteristics of variable parameters in rotor system with rub-impact fault

In this paper a finite element (FE) model of dual-span rotor system with rub-impact at fixed limiter is established. The system motion characteristics in different rotating speeds and rub-impact rod stiffness are investigated numerically by using Hilbert-Huang transform, a relative novel time-frequency analysis method. The results show that the effects of variables on system motion patterns, response properties and rub-impact severity differ in degrees. Some conclusions are achieved which may be useful to deeply understand dynamic properties of dual-span rotor system and detect rub-impact fault accurately and effectively.