多自由度裂纹转子系统非线性动力学特性分析  

Nonlinear dynamic behavior analysis for a cracked multi-DOF rotor system

作　　者：于海[1] 陈予恕[1] 曹庆杰[1] 

机构地区：[1]哈尔滨工业大学航天学院,哈尔滨150001

出　　处：《振动与冲击》2014年第7期92-98,共7页Journal of Vibration and Shock

基　　金：自然科学基金重点项目(10632040);面上项目(11072065)

摘　　要：大型旋转机械转轴裂纹具有复杂的高维非线性特征,由此产生的机械故障时有发生。根据航空发动机低压转子系统,利用拉格朗日原理建立了具有26个自由度的含有裂纹故障的高维非线性动力学模型。引进改进的POD方法成功将该系统降为具有两个自由度含有特征的低维非线性系统。数值模拟结果显示降维系统具有与原系统一致的非线性动力学特征,表明本方法对解决高维非线性问题具有较好的有效性。此外,还利用C-L方法对其进行分岔分析,讨论了系统参数与系统动态行为之间的关系,得到了裂纹转子各种不同分岔模式,得到了裂纹二分之一亚谐共振条件下的非线性动力学特性,准确反映了裂纹转子的动力学特征。Crack fault is an often occurring complex high-dimensional nonlinear problem in large rotating machinery systems.Here,a low-pressure rotor system with a pair of liquid film lubricated bearings was modeled into a 26-DOF nonlinear system using Lagrange method.This high dimensional nonlinear system was reduced into a 2-DOF system with a crack fault and oil-film oscillation property by introducing the modified POD method.Numerical simulations demonstrated the effectiveness of the proposed method.the compavison between the computed results of the reduced system and those of the original system showed that both of the two systems have the consistent nonlinear dynamic features.C-L method was also employed to obtain the dynamical behaviors of the reduced system,they reflected the dynamic property of a cracked rotor system.

关 键 词：裂纹转子 降维 亚谐振动 C-L方法 

分 类 号：O32[理学—一般力学与力学基础] N93[理学—力学]