On the Nonlinear Dynamic Behavior of a Rotor-Bearing System
The nonlinear dynamic behavior of a rotor-bearing system is analyzed based on a continuum model. The finite element method is adopted in the analysis. Emphasis is given on the so called “Oil-Whirl phenomena” which might lead to the failure of the rotor system. The dynamic response of the system in unbalanced condition is approached by direct integration method and mode superposition method, it is found that a typical “Oil-Whirl phenomenon” is successfully produced. Furthermore, the bifurcation behavior of the Oil-Whirl phenomenon that is much concerned in recent nonlinear dynamics research is analyzed. The rotor-bearing system is also examined by the simple discrete model. Significant differences are found between these two models. It is suggested that a careful examination should be made in modeling such nonlinear dynamic behavior of the rotor system.