Nonlinear Characteristics of Rub-Impact Rotor-Bearing System with Slowly Varying Mass

A nonlinear dynamic model of rub-impact rotor-bearing system with slowly varying mass was set up. 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 rub-impact rotor-bearing system with slowly varying mass. The unstable form of it is saddle-node bifurcation. There are periodic-doubling bifurcation and saddle-node bifurcation at different rotate speed. In the region of double critical rotate speed, the main motion of the system is quasi-periodic motion. The conclusions provide theoretic basis reference for the fault diagnosis of the rotor-bearing system.