Longitudinal Ultrasonic Guided Waves for Monitoring the Minor Crack of Rotating Shaft with Galfenol Transducer

The safety of rotating machinery is important for the manufacture industry. As the core component of the rotating machinery, the rotating shaft with racks or damages will lead to the terrifically disaster. Compare with the vibration signal diagnosis of the rotating shaft, it presents a novel method to detect crack on rotating shaft with longitudinal ultrasonic guided wave. In the view of elastic wave propagating mechanism in the cylindrical waveguide, it discuss the influence of rotor dynamics effect on the system, from the govern equation of wave propagating in rod, it consider the lateral effect of the rotating shaft, the reflection and transmission of the guided wave in the waveguide. It takes the Galfenol transducer as a pulse-echo transducer to detect the crack on the rotating shaft. Finally, it gives the simulation of experiment results, the results indicated the method can locate the crack accurately after conducting the wavelet transformation on the difference between cracked and non-cracked rotating shaft experiment waveform