Taking the Jeffcott rotor with elastic support as the research object

the dynamic differential equation of rotor-foundation external random excitation system with rubbing faults was built in consideration of the effect of the external random excitation on the foundation and rubbing faults between stator and rotor. The numerical simulation was employed to obtain the system responses with the effect of the external random excitation

and the axis orbit

frequency spectrum and Poincaré sections were used to anlyse the effect on rotor-foundation system with the variation of the external random excitation. The results show that: the vibration mode (such as frequency and waveform) could be changed by the intensity and spectral width of the external random excitation and frequency of the external periodic excitation. And it will cause complex dynamic behaviors of rotor such as cycle

period doubling and chaos.