Bifurcation and nonlinear dynamic analysis of united gas-lubricated bearing system

This paper studies the bifurcation and nonlinear behaviors of a united gas-lubricated bearing (UGB) system by a hybrid numerical method combining the differential transformation method and the finite difference method. The analytical results reveal a complex dynamic behavior comprising periodic, sub-harmonic, quasi-periodic and chaotic responses of the rotor center. Furthermore, the results reveal the changes which take place in the dynamic behavior of the bearing system as the rotor mass and bearing number are increased. The current analytical results are found to be in good agreement with those of other numerical methods. Therefore, the proposed method provides an effective means of gaining insights into the nonlinear dynamics of UGB systems. (C) 2011 Elsevier Ltd. All rights reserved.