可倾瓦轴承-转子系统非线性动力行为

Analysis of Nonlinear Dynamic Behaviors of Rotor System Supported by Tilting-Pad Journal Bearings

运用变分约束原理,在动力积分、迭代过程中修正了流体润滑的Reynolds方程的变分形式,使其等价为变分不等式。运用八节点等参有限元方法,计算了单块瓦的非线性油膜力,并通过组装技术求解得到5瓦可倾瓦滑动轴承的非线性油膜力。运用Poincar映射和Runge-Kutta方法,分析了5瓦可倾瓦滑动轴承支承的对称刚性转子系统的不平衡响应。数据结果显示了可倾瓦轴承-转子系统的周期解、倍周期解和混沌运动等非线性现象。

In order to calculate the nonlinear oil force of each pad of tilting-pad journal bearing in a single pad coordinate,the variational constraint approach is used in this paper.According to the physical characteristic of the oil film,an isoparametric finite element with eight nodes method is adopted to convert the Reynolds equation continuously to the discrete form of finite dimensional algebraic variational equations satisfying certain constraint conditions at each step of the dynamic integration and iteration.The oil force of five-pad tilting-pad journal bearings is obtained by the assembly method.In order to analyze the unbalanced response behavior of the symmetrical rigid rotor dynamic system supported by the five-pad tilting-pad journal bearing,the Runge-Kutta method and a Poincare map are used.The numerical results show complex nonlinear behaviors of the system,such as periodic,period-doubling,chaos,and etc.