Numerical Analysis And Experimental Study Of The Dynamical Characteristics Of Rotor Support Systems

This paper investigates the vibration features and the nonlinear dynamic phenomena of bifurcation and chaos from rotor support system faults including rubbing and coupling fault of support looseness and rubbing based on the theory of modern nonlinear dynamics and the theory of rotor dynamics. Experimental results ware obtained from a rotor experimental bench to compare with and verify computation results.First, considering the influence of bearing oil-film force and nonlinear rubbing force, a mechanical model of a nonlinear rubbing rotor system is set up. The dynamic behavior of this model is studied using the method of numerical integration. And the effects of the change of the rotating speed, imbalance and speed influence factors on the complex nonlinear dynamic phenomena of the system are analyzed. Then, a mechanical model with coupling fault of support looseness and rubbing is set up. Using the method of numerical integration, the dynamics of the coupling faults are studied, and the effect of imbalance on dynamic behavior of the system is investigated. Finally, applying rotor experimental bench in the lab, and doing the nonlinear experiments of the rubbing and coupling fault of support looseness and rubbing of the single-disk rotor system. Based on the experiment results, conclusions can be drawn that rubbing is nonlinear phenomena, causing the wide frequency range vibration, including various harmonic components. When the rotating speed is lower than the critical speed, the second and third harmonic components will appear. On the contrary, there may be sub-frequency vibration when the speed is higher than the critical speed. Analysis and comparison of the experimental data show that the dynamic response of the rubbing and coupling fault of support looseness and rubbing of the rotor system conforms to the theoretical computational results in different speed range.