Fault Diagnosis Method of Rub-impact in Rotor System Based on Nonlinear Output Frequency Response Function

Nonlinear output frequency response function is introduced to fault diagnosis of rotor system with rub-impact. NOFRF values in the rotor and the stator rotor system with different gap are compared, and the experimental verification is carried out. The experiment results show that the NOFRF value is very sensitive to different rubbing gap. Therefore, the sensitivity of NOFRF value to the rubbing fault can be used to effectively distinguish the rub impact fault in the rotor system, and identify the severity of the rubbing fault in the rotor system.