Vibration response analysis of rubbing faults on a dual-rotor bearing system

摘要

In order to study the dual-rotor system's rubbing fault, a new dynamic model is established. The unbalance and the rubbing faults are modeled, respectively. Considering the softening characteristics of casing, the Lankarani-Nikravesh model is utilized to describe the impact force between the disk and fixed limiter. The numerical integral method is applied to obtain system's dynamic behavior, and the characteristics of the rubbing faults are analyzed by time-domain waveform, 3D waterfall plot and spectrum cascades. The influences of rotational speed ratio, initial clearance, mass eccentricity and inter-shaft bearing stiffness on the dynamic characteristics are investigated. The vibration displacement of the low-pressure rotor is collected from the impact experiment performed on a dual-rotor test rig. The analysis result of simulation is identical with the experiment result. Consequently, this method can be used to study characteristics of rubbing faults of dual-rotor bearing system efficiently.