航空发动机弹性支承结构的动力学特性及其振动传递机理研究

Flexible support assembly is commonly used in aero-engine, which is one of the very important components for the rotor system, and greatly affects the dynamic characteristics of the rotor system and even the vibration performance of the whole engine. Due to the complex structure characteristics and multi-interface transmission path and the multiple excitation environments (outer excitation forces due to maneuvering flight and landing impact, and inner excitation forces from shaft), it has greatly increased the difficulty of dynamic analysis and design for the flexible support assembly. The analysis method for the dynamic characteristics of the flexible support assembly in aero-engine is proposed, taking into account the complex structure characteristics and the performance degradation due to its multiple excitation environments. Based on the studies of rotor dynamic and vibrations, the excitation forces and vibrations on the flexible support assembly due to the shaft are obtained analytically. And then, the investigation on the deformation and strain energy distribution, the coupling dynamic characteristics and the vibration transmission mechanism for the flexible support assembly and its components are carried out, which are experimentally revised and verified. The study will be useful for the dynamic design for the flexible support assembly, as well as to predict and evaluate vibration characteristics of the flexible support assembly and also the whole system with flexible supports.

弹性支承结构是航空发动机转子系统的重要结构件，其动力学特性与转子系统乃至整机的动力学性能和振动问题密切相关。弹支结构具有复杂的结构特征和多界面传力路径，这大大增加了其动力学及振动特性分析与设计的难度。此外，弹支结构长期处于复杂多源激励环境（机动飞行与着陆冲击载荷、转轴激励等）中，一旦出现支承负荷状态劣化，其性能退化问题突出，严重影响整机的安全稳定性。基于此，本项目以航空发动机弹支结构为研究对象，提出其动力学特性分析方法；在转子-支承系统动力学与振动研究的基础上，深入研究机动飞行与着陆冲击、转轴激励等因素对弹支结构振动行为的影响，掌握弹性支承各结构件的变形和应变能分布及其耦合动力学特性，揭示弹性支承各结构件的振动响应及传递规律。本项目研究为航空发动机转子系统及其弹性支承结构的动力学设计、整机和结构振动预估、评价和控制等提供理论支撑。

弹性支承结构是航空发动机转子系统的重要结构件，直接影响到转子系统动力学特性乃至整机振动性能。然而，弹支结构复杂的结构特征及长期处于转轴激励、机动飞行与着陆冲击等复杂多源激励环境，大大增加了其动力学分析与设计难度。.本项目以航空发动机弹支-转子系统为研究对象，基于能量法和有限单元法建立含有弹支结构的转子系统动力学模型，分析了支点特性对转子系统模态振型及应变能分布影响规律；进一步，结合有限元法和多体动力学理论建立了弹支转子刚柔耦合动力学模型，在此基础上计入了轴承非线性的影响，分析了转子、轴承的耦合振动，并开展模型验证；在弹性支承鼠笼应变分布分析基础上，提出了基于弹性支承鼠笼应变测试的载荷辨识方法，并完成了初步的工程应用探索。.通过理论分析、数值模拟与实验验证相结合的方法，分析了转子稳态和瞬态不平衡、不对中、碰摩等转轴激励对转子系统振动响应及弹支鼠笼载荷及应力影响，分析了机动飞行转弯状态转子系统动力学响应特性；开展了在支点冲击激励以及基础激励下转子振动以及弹性结构振动响应、支反力、鼠笼应变特性及其传递特性研究。掌握了不平衡、不对中、碰摩等转轴激励和机动飞行、支点冲击、基础激励等外部激励对弹支结构振动、应变分布及其与转子耦合特性的影响规律。.本项目研究为航空发动机转子系统及其弹性支承结构的动力学设计、支点载荷测试及整机和结构振动预估等提供理论支撑。