共用支承-双转子系统振动耦合机理及响应特性

针对带有涡轮级间共用承力框架的双转子系统，采用机械阻抗理论定量描述结构质量/刚度分布特征，建立了复杂转子系统振动耦合机理模型，并提出了针对共用支承-双转子系统的振动耦合点确定方法，以及交互激励瞬态响应仿真方法。仿真结果表明：共用支承-双转子系统振动耦合的力学本质，是转子与支承结构振动交互作用下的动力响应耦合，既包括共用支承结构振动基础激励带来的振动耦合力学行为，又包括多转子交互激励下多频率组合的振动响应耦合力学行为。其中基础激励下耦合程度与支承机械阻抗及转子振型有关，转子间交互激励下耦合程度则受被激转子模态振型影响，被激转子刚体模态振型对基础振动敏感，在激励转子作用下更易产生转子交互激励下振动耦合。

Vibration coupling mechanism and response characteristics of shared support dual-rotor system

For the dual-rotor system with mid turbine frame, the mechanical impedance theory was used to quantify the structural mass/stiffness distribution characteristics, and the vibration coupling mechanism model of complex rotor system was established, then the vibration coupling point determination and interactive excitation transient response simulation methods for shared support dual-rotor system were proposed. The simulation results showed that the mechanical essence of shared support dual-rotor system vibration coupling lied in the dynamic response coupling under the vibration interaction between rotor and support structure, including vibration coupling mechanical behavior caused by foundational vibration of shared support structure as well as interaction excitation of multiple rotors. Vibration coupling level under foundational excitation was related to support mechanical impedance and rotor mode shape, and the vibration coupling level under rotor interaction excitation was affected by excited rotor mode shape. The rigid body mode shape of excited rotor was sensitive to foundation vibration, making it easier to produce rotor interaction excitation vibration coupling under excitation of another rotor.