Theoretical–experimental study on a rotor with a residual shaft bow

This paper presents the influence of the residual shaft bow on the rotor longitudinal responses through simulation and experiment. Dynamics model of a warped rotor was established, and the influences of residual shaft bow on rotor vibration in different cases were simulated. The simulation results show that the residual shaft bow can seriously affect the rotor vibration as the eccentricity and the damping ratio are relatively small. Conversely, the influence will be extremely small. Simultaneously, a three-span double-disk rotor test rig was developed, and the experimental studies were carried out. The experimental signals of the rotor with multi-fault were collected, and the wavelet and nonlinear manifold learning methods were employed to extract the fault features. Then, the faults were identified by utilizing the principal component analysis method, and the fault signal of the residual shaft bow was obtained. The test modified equation of the rotor with residual shaft bow was proposed. The experimental and simulation results are consistent, and also verify the validity of the equation of motion.

► Wavelet, ISOMAP and PCA were utilized to identify the residual shaft bow response.
► The minimum value of residual shaft bow and damping ratio was found.
► Residual shaft bow response test modified equation is proposed.