航空发动机整机耦合动力学模型及振动分析

面向航空发动机整机振动, 建立了航空发动机转子-滚动轴承-机匣耦合动力学模型. 该模型具有如下特点: (1)考虑转子、滚动轴承及机匣之间的耦合作用; (2)考虑了实际航空发动机的弹性支承及挤压油膜阻尼效应; (3)将转子考虑为等截面自由欧拉梁模型, 运用模态截断法进行分析; (4)考虑了滚动轴承间隙、非线性赫兹接触力以及变柔性VC(Varyingcompliance)振动; (5)考虑了转子与机匣之间的碰摩故障. 运用数值积分方法研究了航空发动机的整机振动规律, 包括: 滚动轴承VC振动分析、弹性支承刚度对耦合系统临界转速的影响、转轴模态截断阶数NM对系统响应的影响分析、挤压油膜阻尼器参数对系统响应的影响分析、突加不平衡的瞬态响应分析以及转静碰摩故障特性分析等. 

COUPLING DYNAMIC MODEL AND DYNAMIC ANALYSIS FOR WHOLE AERO-ENGINE

In this paper, a rotor-ball baring-stator coupling dynamic model for whole aero-engine vibration is established. The main characteristics of the new model are as follows: 1) the coupling effect between rotor, ball bearing and stator is considered fully; 2) the flexible support and the squeeze film damper (SFD) are considered; 3) the rotor is considered as Equisection Euler Free Beam model, and its vibration is analyzed through cutting limited modes; 4) nonlinear factors of ball bearing are modeled, such as the clearance of bearing, nonlinear Hertzian contract force, and the varying compliance; 5) rubbing fault between rotor and stator is considered. In this paper, the numerical integral method is employed to obtain system's responses, and the whole aero-engine vibration characteristics are studied. Research topics are investigated, such as ball bearing VC vibration analysis, effect of elastic support stiffness on the system critical speeds, effect of cutting modes number on system responses, sudden-adding imbalance transient response simulation, and rotor-stator rubbing fault characteristics analysis.