考虑支柱轴向位移和纵向弯曲的双轮前起落架摆振特性分析  

Shimmy characteristics of dual-wheel nose landing gear considering the axial and longitudinal motions of strut

作　　者：高相国 卢翔[2] 单泽众 GAO Xiangguo;LU Xiang;SHAN Zezhong(College of Aeronautical Engineering,Civil Aviation University of China,Tianjin 300300,China;School of Transportation Science and Engineering,Civil Aviation University of China,Tianjin 300300,China)

机构地区：[1]中国民航大学航空工程学院,天津300300 [2]中国民航大学交通科学与工程学院,天津300300

出　　处：《振动工程学报》2025年第3期517-528,共12页Journal of Vibration Engineering

基　　金：国家自然科学基金资助项目(U2033209);中国民航大学研究生科研创新项目(2022YJS041)。

摘　　要：起落架支柱轴向压缩将直接导致系统刚度和转动惯量发生变化,但现有前起落架(nose landing gear,NLG)摆振模型中大多忽略支柱轴向位移的影响。建立了考虑支柱轴向位移和纵向弯曲的六自由度双轮前起落架摆振非线性动力学模型。应用分岔理论研究了支柱轴向位移对摆振区域的影响,并将缓冲器最大压缩行程分别与滑跑速度、垂向载荷和机轮转动惯量进行组合,对组合参数进行双参数分岔分析。采用四阶Runge-Kutta法和快速傅里叶变换在摆振稳定区内进行时频特性计算,研究了支柱扭转、侧向弯曲和纵向弯曲摆振自由度之间的相互作用。结果表明:在一定工况下,考虑支柱轴向位移影响后,支柱扭转摆振和侧向摆振区域均有缩小趋势。双轮前起落架摆振双稳态区域内,当初始激励接近零平衡状态时,纵向摆振发生在2倍扭转振动固有频率附近;而当初始激励远离零平衡状态时,纵向摆振发生在2倍侧向振动固有频率附近。The axial compression of the landing gear strut can directly lead to the change of system stiffness and rotational inertia,but the effect of strut axial displacement is mostly ignored in existing models of nose landing gear shimmy.A nonlinear dynamic model of six-degree-of-freedom dual-wheel nose landing gear shimmy with axial displacement and longitudinal bending of struts is established.The bifurcation theory is applied to study the effect of introducing axial displacement on the shimmy region,and the maximum compression stroke of the buffer is combined with sliding speed,vertical load,and wheel rotational inertia,respectively.The combined parameters are analyzed by two parameter bifurcation.The fourth order Runge-Kutta method and fast Fourier transform are used to calculate the time-frequency characteristics in the stable shimmy region,and the interaction between the degrees of freedom of torsion,lateral bending,and longitudinal bending of the strut is studied.The results show that under certain conditions,considering the influence of axial displacement of the strut,the areas of torsional and lateral shimmy of the strut have a tendency to shrink.In the bistable region of double wheel nose gear shimmy,when the initial excitation is close to zero equilibrium state,the longitudinal shimmy occurs near 2 times the natural frequency of torsional vibration.When the initial excitation is far from the zero equilibrium state,longitudinal shimmy occurs near 2 times the natural frequency of lateral vibration.

关 键 词：前起落架 非线性摆振 六自由度模型 双参数分岔 振动频率 

分 类 号：V226.4[航空宇航科学与技术—飞行器设计]