非线性转子—轴承系统的动力学特性及稳定性

DYNAMIC CHARACTERISTICS AND STABILITY OF NONLINEAR ROTOR-BEARING SYSTEM

研究非线性转子—轴承系统的动力学特性及稳定性。采用改进的自由界面模态综合技术给出一种自由度降阶方法 ,该方法将非线性油膜力及非线性自由度保留在物理空间 ,以增加非线性分析的精度 ,使降阶系统仍具有局部非线性特征。基于打靶法及将延续算法和打靶法相结合的轨迹预测追踪算法 ,研究系统非线性不平衡响应 。

Dynamic characteristics and stability of nonlinear rotor-bearing system are analyzed. A modified modal synthesis technique is presented to reduce degrees-of-freedom of a finite element model of flexible rotor system. In order to increase the numerical accuracy, nonlinear oil film forces and nonlinear degrees-of-freedom of the system are remianed in physical space. The reduced system keeps the local nonlinearities. The nonlinear unbalance responses of the system are obtained by using shooting method and path-following technique. The local stability and bifurcation behaviors of T periodic motions are analyzed by the Floquet theory. The numerical schemes of this study are applied to a flexible rotor system. The numerical examples show that the schemes of this study not only save computing efforts but also have good precision.