Dynamic analysis of nose landing gear shimmy considering hydraulic damping characteristics

考虑油液阻尼特性的前起落架摆振动力学分析

¹ State Key Laboratory of Mechanics and Control for Aerospace Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
² Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China

Received: 28 April 2025

Abstract

Large and medium-sized aircraft widely employ nose wheel hydraulic steering systems to achieve steering control and shimmy suppression. The damping characteristic of the steering system is the core factor for effective shimmy control of the nose landing gear, directly influencing its dynamic performance. In order to investigate the influence of the hydraulic characteristics of the steering system on the shimmy behavior of the nose landing gear, this paper establishes the hydraulic model of the nose wheel steering system and the dynamic shimmy model of the nose landing gear for a specific aircraft type. Through simulation analysis, the oil damping torque characteristics of the hydraulic system and its coupling with the Coulomb friction torque are discussed, and the time-frequency dynamic characteristics of the front wheel swing angle under the anti-swing state are further studied. The results indicate that: The hydraulic damping of the steering system exhibits significant nonlinear characteristics during shimmy suppression. Appropriately increasing the system's Coulomb friction torque can effectively compensate for the limitations arising from the nonlinearity of the hydraulic damping. This research provides valuable references for optimizing the damping parameter design of steering systems and offers important engineering guidance for improving ground taxiing stability.

摘要

大、中型飞机广泛采用前轮液压操纵系统, 以实现前轮转向的控制和对摆振现象的抑制。操纵系统的阻尼特性是实现飞机前起落架摆振有效控制的核心, 会直接影响起落架的动力学性能。为探究油液阻尼对前起落架摆振特性的影响, 以某型飞机为研究对象, 分别建立了前轮操纵系统的液压模型和前起落架摆振动力学模型。通过仿真分析, 探讨了液压系统的油液阻尼力矩特性及其与库仑摩擦力矩的耦合作用, 并进一步研究了减摆状态下前轮摆角的时频动态特性。结果表明: 液压操纵系统的油液阻尼在减摆状态下具有显著的非线性特性, 适当增大系统的库仑摩擦力矩可以有效补偿液压系统阻尼非线性的不足, 为操纵系统阻尼参数的优化设计提供重要参考, 有助于提升飞机的地面滑跑稳定性。