共用支承-转子结构系统振动耦合特性分析

针对带有涡轮级间共用承力框架的转子系统，为准确描述转子-共用支承-转子（简称共用支承-转子结构系统）之间的振动特性，采用转子截面横向和角向振动特性耦合动力学模型，振动耦合产生机理及影响规律进行研究。理论分析结果表明:转子支点的动态响应对其他转子的支点动刚度特性及转子振动响应特性具有一定影响，共用支承结构振动响应对转子系统振动特性的计算误差超过10%，因此，在共用支承-转子结构系统的临界转速和振动响应计算分析中，需要考虑2个转子与共用支承结构的振动耦合影响。对于涡轴发动机共用支承-转子结构系统的有限元仿真计算结果表明:由于存在共用承力框架，2个转子之间将发生振动耦合，系统产生耦合振型，某一转子转速将会影响另一转子所激起的系统共振临界转速；并对共用承力框架结构的隔振特性也有影响，2个转子共同激励下振动响应与转子单独激励相比，在承力框架安装边上的动载荷以及载荷传递系数均大幅度提高。 

Coupling vibration characteristics analysis of shared support-rotors system

The rotor system with turbine mid frame is researched as an objected, and the dynamic model with coupling vibration in transverse and angular degree was employed to reveal the vibration coupling mechanism and influence in shared support-rotors system. It is pointed that support response of one rotor can influence the bearing dynamic stiffness and rotor dynamic characteristic of another, and the calculation error of traditional rotor dynamic modeling exceed 10%, so the vibration coupling should be considered when analyzing critical speed and dynamic response in the rotor system with mid frame. The finite element calculation results for the shared support-rotors system in turbo-shaft engine exhibit that the coupling modes will arise, and the speed of one rotor can affect the critical resonant speed excited by another. The vibration isolation characteristics of mid turbine can also be affected due to the coupling vibration, and compared with non-coupling system, the dynamic response and load-transferring coefficient both remarkably increase.