The Nonlinear Dynamic Characteristics of a Cracked Rotor-Bearing System with Initial Bend Deformation

The dynamic model of a cracked rotor-bearing system with initial bend deformation was established and a kinetic equation is set up to express the vibration characteristics. Numerical method is adopted to analyze the effects of the depth of crack and the initial bend deformation on the vibration response of the rotor system. The results indicate that, the chaotic region near the critical speed of the rotor with initial bend deformation is wider than that without initial bend deformation, and the chaotic region become slowly as the depth of crack increases. The dynamic phenomena of initial bend deformation play a dominant role in the case of shallow cracks, there is a short region for period-twelve, and most of them are chaotic motion. The vibration response of the rotor system with different initial bend deformation appear periodic and chaotic states alternate as the depth increase. It indicated that this research may contribution to further understanding of the failure mechanism of such a rotor-bearing system.