中文摘要：

分析了轴承-转子系统的稳定性和分岔，基于系统可观测状态信息给出1种求解系统周期解及识别周期解稳定性的方法，同时将该方法与Floquet理论相结合分析系统周期解的稳定性及失稳分岔形式，将转速作为分岔参数分析系统响应的周期、拟周期、多解共存和跳跃现象．结果表明，采用该方法计算系统周期解及稳定性时，利用系统可观测稳态和瞬态信息，即可求解出系统Jacobian矩阵而无需实时求解轴承非线性油膜力的Jacobian矩阵．与传统PNF方法相比，该方法不仅具有很高的精度而且可以节约计算量，同时可以预测追踪随控制参数变化的系统周期解及其稳定性，可用于指导轴承-转子系统的非线性动力学设计．

英文摘要：

Stability and bifurcation of sliding beating-rotor system are analyzed. A numerical method is proposed to calculate the periodic solution and identify its stability of sliding beating-rotor system based on observed states. Combined with Floquet theory, the method is used to analyze the stability and bifurcation of periodic solution. Taking the rotating speed as bifurcation parameter, periodic, quasi-periodic, co-existent and jumped solutions of the system are analyzed. The results show that the proposed method suffices to obtain the Jacobian of the system using the observed steady and transient information, so it is unnecessary to solve Jacobian of nonlinear oil film force of sliding bearing. It has high precision and saves computational cost compared with traditional PNF method. Meanwhile the method can trace periodic solution and identify stability which vary with control parameter. Numerical examples show that the proposed method can direct the nonlinear dynamics design of bearing-rotor system.