Abstract
In order to detect a transverse crack due to fatigue of rotor, this paper investigates theoretically and experimentally the change of resonance curve of amplitude and phase lag for various angular positions of unbalance vs crack angular position. In the analysis, stiffness of the crack rotor is represented by higher order sinusoidal function and the equation of motion is solved by using perturbation method. Each element of the solution is discussed from the view point of detection of crack and the amplitude and phase angle are compared with the experimental results. The effect of crack on the amplitude and phase angle of the resonance is discussed. Finally the characteristics of the crack is clarified and the guide for detecting the crack is proposed.
