Numerical and experimental investigations of flexural vibrations of a rotor system with transverse or slant crack

Flexural vibrations of a rotor system with transverse or slant crack are analyzed under torsional excitation by numerical simulation and experiment. Numerical results show that combination frequencies of the rotating speed and the torsional excitation frequency are prominent in the flexural responses of a slant-cracked rotor, but too weak to be identified for a transverse-cracked rotor. In order to verify the results, an experimental setup is installed to simulate the cracked rotor system and a special structure is designed to exert the torsional excitation on the cracked rotor. The experimental results present almost identical characteristic features about the combination frequencies to the numerical results. The numerical and experimental investigations demonstrate these features can be used to distinguish between the transverse crack and the slant crack on the shaft of a rotor system.