Abstract
In this paper, a method to solve a complex nonlinear vibration system is proposed by using both component mode synthesis method and perturbation method to save computation cost. That is, the system is divided into some components and these are approximately transformed to modal coordinate system with nonlinearity under the assumption that the modes shape does not change, then equations of every modes are solved by using a perturbation method. These solutions are synthesized to the whole system and the solution for the whole system is obtained for the modal coordinate system. Finally, it is translated to the physical coordinate system. This method is applied to a vibration analysis of nonlinear rotor and bearing-casing system. In order to illustrate the accuracy and computation time of the proposed method, the results obtained are compared with those obtained by the finite element method.
