Stability of the Two-span Rotor-bearing System Periodic
with Coupling Faults of Crack and Rub-impact

LUO Yuegang^{1, 2}  WEN Bangchun²

(1. Research Institute of Mechanism Electron and Control Engineering, Dalian Nationalities University, Dalian 116600;
2. College of Mechanical Engineering and Automation, Northeastern University, Shenyang 110004)

Abstract: A dynamic model is set up for the two-span rotor-bearing system with coupling faults of crack and rub-impact. Using the continuation-shooting algorithm for periodic solution of nonlinear non-autonomous system, the stability of the system periodic motion is studied by the Floquet theory. The unstable form of the rotor system with crack fault is period-doubling bifurcation, and that with rub-impact fault is Hopf bifurcation. The unstable form of the rotor system with coupling faults is Hopf bifurcation when the depth of crack is smaller. The influence to the response of the system increased along with the depth of crack, the unstable form of the rotor system with coupling faults is period-doubling bifurcation. The conclusions provide theoretic basis reference for the failure diagnosis of the rotor-bearing system.

Key words: Rotor-bearing system  Crack Rub-impact  Coupling faults  Stability  Bifurcation

CLC No: O322

国家自然科学基金资助项目(50535010, 50775025). Received 20070406, received in revised form 20070914

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