Hilbert–Huang transform for detection and monitoring of crack in a transient rotor

The dynamics and diagnostics of a cracked rotor have been gaining importance in the recent years. Vibration monitoring during start-up or shut-down is as important as during steady-state operations to detect cracks especially for machines such as aircraft engines which start and stop quite frequently and run at high speeds. In the present study a relatively new signal processing technique namely Hilbert–Huang transform (HHT) has been applied to transient response of a cracked rotor and few interesting results have been observed. And in all cases it has been found that HHT appears to be a better tool compared to fast Fourier transform and continuous wavelet transform for crack detection in a transient rotor.