Time-Frequency Characteristics Analysis on Vibration Signals of a Three-Supported Rotor System with Misalignment

Abstract

Abstract. In light of the complex and non-stationary characteristics of misalignment vibration signal, this paper proposed a novel method to analyze in time-frequency domain under different working conditions. Firstly, decompose raw misalignment signal into different frequency bands by wavelet packet (WP) and reconstruct it in accordance with the band energy to remove noises. Secondly, employ empirical mode decomposition (EMD) to the reconstructed signal to obtain a certain number of stationary intrinsic mode functions (IMF). Finally, apply further spectrum analysis on the interested IMFs. In this way, weak signal is caught and dominant frequency is picked up for the diagnosis of misalignment fault. Experimental results show that the proposed method is able to detect misalignment fault characteristic frequency effectively.

Spectrum Analysis of a Coaxial Dual-Rotor System with Coupling Misalignment

“…Reddy and Sekhar [9] studied a technique that uses torque measurements to detect and monitor coupling misalignment. Qi et al [10] proposed a novel method to analyse in time frequency domain under different misalignment conditions, and the experimental results show that the proposed method is able to detect misalignment fault characteristic frequency effectively. Patel et al [11][12][13] investigated the influence of misalignment and its type on the forcing characteristics of flexible coupling by the full spectrum.…”