Dynamics of Pedestal Looseness Rotor System Near the Critical Speed Region

A new type of dynamic model for pedestal looseness rotor system was built, and the dynamics of the rotor system in resonance region was analyzed by using KBM method. Some dynamic characteristics of pedestal looseness rotor system were found. The natural frequency of the fault system descends and the resonance region becomes greater,the highorder harmonic is evident, the system has 'soft' nonlinear characteristic. The affections on the faulting system of some system parameters, such as pedestal stiffness and shaft bending stiffness,were studied. The theoretrcal analysis comforms to the experimental results.