Abstract: The characteristics of coupled bending-torsional- pendular coupling vibrations of rotary shaft systems are studied to improve the safety of rotary shaft systems. It is deduced that the general differential equation of bending-torsional-pendular coupling vibration about rotor with the gyroscopic moment. On the basis of this equation, the general differential equations of coupled bending, torsional and pendular nonlinear vibration about rotor with unbalance character and rubbing character are deduced. The bifurcation and chaos behavior especially the influence on bifurcation and chaos behavior of impact and rub-bing fault rotor system caused by the parameters of rotor rotat-ing speed are analyzed by using the numerical value analysis method. The analysis results caw provide the theoretical bases for safely operating and identifying the combination-resonance fault of the rotors.

Key words: Bending-torsional-pendular, Coupling, Nonlinear, Rubbing, Vibrations