Fault Detection of Nonlinear Rotor-Bearing Systems by Using the Nonlinear Output Frequency Response Functions (NOFRFs)

In this study, the fault detection of nonlinear rotor-bearing systems is investigated by using the frequency analysis approach. The Nonlinear Output Frequency Response Functions (NOFRFs) of the nonlinear rotor-bearing system are evaluated and used to diagnosis the abnormal conditions of the bearings. Both simulation and experimental studies are conducted to demonstrate the application of the NOFRFs based fault detection method. The results indicate that the higher order NOFRFs are sensitive to the faults of the bearings and independent of the imbalance distance of the rotor. The monotonous change of the NOFRFs with the severity of the faults can be used to effectively quantify the severities of defects in the rotor-bearing systems.