Stability of Periodic Motion of Nonlinear Elastics Rotor-Bearing System with Coupling Faults of Pedestal Looseness and Rub-Impact

A dynamic model of the nonlinear elastics rotor-bearing system with coupling faults of pedestal looseness and rub-impact was set up, taking the linearity and cube item as the physics nonlinear factors. The periodic solution of system was analyzed by continuation-shooting algorithm for periodic solution of nonlinear non-autonomous system, and the stability of system periodic motion and unsteady law are discussed by Floquet theory. There exist periodic, quasi-periodic and chaotic motions in the response of the rotor-bearing system with coupling faults. The unstable form of it is saddle-node bifurcation. In the region of double critical rotate speed, the main motion of the system is chaotic motion. The conclusions provide theoretic basis reference for the fault diagnosis of the rotor-bearing system.