Detection of a Rotor Crack Based on the Nonlinear Vibration Diagnosis Using Periodic Excitation Available to Purchase

Detection of a rotor crack based on the nonlinear vibration diagnosis using periodic excitation force is investigated. Due to the open-close mechanism of the crack, the equations of motion of a cracked rotor have linear and nonlinear parametric terms. When a periodic excitation force is applied to the cracked rotor, various kinds of resonances due to the unique vibration characteristics of a crack. Furthermore, types of resonances, resonance points and dominant frequency component of these resonances are clarified theoretically and experimentally. These results enable us to detect a crack on-line without stopping the system.