双转子系统动静碰摩动力学研究与基于振动加速度的实验验证  

Dynamics of rub-impact of dual-rotor systems and the experimental verification based on vibration accelerations measurement

作　　者：王南飞[1] 蒋东翔[1] 韩特[1,2] 徐洪志[1] 

机构地区：[1]清华大学电力系统和发电设备控制及仿真国家重点实验室,北京100084 [2]中航工业航空动力控制系统研究所,江苏无锡214063

出　　处：《振动与冲击》2017年第14期71-76,97,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金(11572167)

摘　　要：基于航空发动机动静碰摩故障的特点,建立双转子系统动静碰摩的动力学模型。模型中充分考虑机匣与轮盘碰撞时的弹性变形、接触渗透及弹性阻尼支撑,应用Hertz接触理论和库伦模型,建立干摩擦情况下双转子系统动静碰摩故障时的运动微分方程。运用四阶经典Runge-Kutta法进行求解,得到碰摩故障下双转子系统的动力学响应。因为实际的航空发动机转子的振动位移不易获取,多是测得轴承座或者机匣的振动加速度,为了提取碰摩状态下轴承座振动加速度特征,建立双转子系统试验台,进行动静碰摩实验,从轴承座测量振动加速度,通过频谱分析和包络谱分析方法,分析了轴承座振动加速度信号中的碰摩特征。结果表明双转子系统动静碰摩时,可将两个激励源的倍频和组合频率成分作为航空发动机动静碰摩故障的典型特征。而且当两个振源的频率值相互接近到20%的时候,双转子系统拍振信号强度较大。动力学仿真和实验取得了很好的一致性,验证了所提出的双转子系统碰摩模型的正确有效性。Based on the rub-impact characteristics of aero-engine, the dynamic model of a dual-rotor system under rub-impact was established. The elastic deformation, contact penetration and elastic damping support during rub-impact between the casing and wheel disk were fully considered. The finite element model and its boundary conditions of a quayside gantry crane were established. The collision force and friction were calculated by utilizing the Hertz contact theory and Coulomb model, then the kinetic differential equation of rub-impact under dry rubbing status was derived. The first ten natural frequencies, the corresponding mode shapes and time-history of displacement responses were given based on the analysis of the modes and dynamic responses of the gantry crane system. The calculation and analysis above are helpful for preventing the gantry crane from working in resonant area and for keeping the oversize dynamic deformation under restraint, which can be applied in designing quayside gantry crane systems. Applying the variable step size fourth order Runge-Kutta method, the mb responses of the dual-rotor system were obtained. As for aero-engine, it may not be accessible to directly detect the displacement signals of the rotor system, and only the acceleration signals on the pedestal are easy to be acquiced. In order to analyse the bearing pedestal acceleration characteristics under rub-impact status, a dual-rotor system test rig was designed. Rub-impact experiments were carried out and the vibration acceleration signals collected from the bearing pedestal were analyzed by means of frequency spectrum and envelop analysis in order to extract the rubbing faults, characteristics. The results indicate that the doubling frequency and combination frequencies from two different exciting sources can be considered as the typical characteristics of rub-impact in aero-engines. The beat vibration usually becomes noticeable when the speed difference between the two dual-rotor speeds is less than 20% of the operating speeds. The

关 键 词：双转子系统 动静碰摩 振动加速度 动力学分析 拍振 振动频谱 包络解调 

分 类 号：V231.9[航空宇航科学与技术—航空宇航推进理论与工程] TH113.1[机械工程—机械设计及理论]