涡桨发动机安装系统振动传递特性测试及分析

Test and Analysis of Vibration Transmission Characteristics ofTurboprop Engine Mounting Systems

涡桨发动机一般采用隔振系统将发动机安装于安装框架上,由安装框架与隔振装置组成的涡桨发动机安装系统的传递特性的测试及分析对于涡桨发动机的减隔振安装设计有重要作用。以某型涡桨发动机安装系统为研究对象,设计专用的发动机假件用于模拟发动机质量、惯量、各安装接头位置和结构形式,专用的隔振系统(减振器及安装框)将各安装构件进行安装,专用的固定装置将发动机隔振系统及发动机假件固定在承力墙上。并采用静动联合加载技术在试验室环境下模拟发动机推力及振动载荷,得到发动机刚体模态与安装系统隔振效率。结果表明:在1阶通过频率处,除滚装状态外,发动机5个自由度方向的隔振效率均在80%以上;侧向/垂向激励下,该隔振系统减振器隔振效率均超过80%,符合相关标准及型号需求。同时,本文形成的试验及分析方法可指导后期外场台架试验研究,并为型号研制奠定技术基础。

The turboprop engine is generally installed in the mounting frame by an isolation system,so the test and analysis of the transmission characteristics of the turboprop engine mounting system are important for the design of the turboprop engine.The turboprop engine mounting system consists of the mounting frame and the vibration isolating device.In this study,a turboprop engine installation system is taken as the research object.A special engine dummy is designed to simulate the engine mass and inertia,and the position and structure of each joint.A special vibration isolation system consisting of absorber and mounting frame is designed to install each mounting member.A special fixing device is designed to fix the engine vibration isolation system and engine dummy to the load-bearing wall.The static and dynamic combined loading technology is used to simulate the engine thrust and the vibration load in the laboratory environment.The engine rigid body mode and the vibration isolation efficiency of installation system are obtained.The results show that at the first pass frequency,the vibration isolation efficiency of the engine in the five degrees of freedom is above 80%except for the roll-on state;under lateral/vertical excitation,the vibration isolation efficiency of the absorber in the isolation system exceeds 80%,which meet the relevant standards and model requirements.The proposed test and analysis methods can guide the experimental research of the external field bench and lay the technical foundation for new model development.