Analysis of the response of cracked rotor with elastic bearings

The dynamic behavior of a cracked rotor with elastic bearings was investigated. The equations of motion of the cracked rotor are derived, then its dynamical behaviors are analyzed numerically. The numerical analysis demonstrates that the displacement response of the vibration of the disc and the acceleration response of the bearing contain 2×, 3×, &middot&middot&middot components, reaching its maximum value when Ω=1/2, 1/3, &middot&middot&middot respectively. The components of high frequency almost disappear in the response of the vibration of the disc when the rotor runs in the supercritical region. But the components of high frequency exist apparently in the acceleration response of the bearing when the rotor runs in the supercritical region. So the 2× component of the vibration of the bearings can be regarded as an evidence of the existence of a crack.