Analysis on dynamic characteristics of multi-strut aircraft under main landing gear coordinated steering

前主起协同转弯下的多支柱飞机动态特性分析

¹ The First Aircraft Design Institute, Aviation Industry Corporation of China, Xi'an 710089, China
² State Key Laboratory of Mechanics and Control for Aerospace Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
³ Key Laboratory of Fundamental Science for National Defense-Advanced Design Technology of Flight Vehicle, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China

Received: 14 July 2025

Abstract

Due to their large fuselage and complex landing gear configuration, multi-strut aircraft faces significant challenges in steering control and stability during ground maneuvers. These factors directly impact flight safety and airport operational efficiency. This study focuses on the AN124 aircraft and develops a mathematical model for ground turning behavior that incorporates the steering dynamics of a multi-strut landing gear system, based on fundamental principles of dynamics. Using this model, the influence of various main gear deflection strategies on turning performance is thoroughly analyzed, with particular attention to turning radius, nose gear steering torque, and tire sideslip. Three steering configurations are examined: deflection of the front main struts alone, deflection of the rear main struts alone, and simultaneous deflection of both front and rear main struts. A comparative analysis is conducted to evaluate the impact of each configuration on key performance metrics. Results show that simultaneous deflection of the front and rear main struts offers the most significant benefits. It not only reduces the sideslip coefficient of the nose wheel but also substantially decreases the aircraft's turning radius. These findings suggest that the coordinated operation of front and rear main struts should be considered in the design of multi-strut landing gear systems to optimize turning performance. This study provides a theoretical basis for the design and optimization of landing gear systems in multi-strut aircraft. It contributes to improving turning performance, reducing maneuvering risks, and enhancing airport operational efficiency.

摘要

多支柱飞机由于其庞大的机身和复杂的起落架布局, 转弯时的操控性和稳定性成为影响飞行安全和机场运行效率的重要因素。以AN124飞机为研究对象, 基于动力学原理构建了考虑转向的多支柱飞机地面操纵转弯数学模型。利用该模型, 深入分析了主起落架不同偏转方式对飞机转弯性能的影响, 重点关注转弯半径、前轮操纵力矩和轮胎侧滑等关键指标。研究了前排主起落架单独偏转、后排主起落架单独偏转以及前后排主起落架同时偏转工况下的转弯特性, 横向对比3种主轮偏转方式对转弯性能的影响。结果显示: 前后排主起同时偏转时可以获得更高的收益, 不但有效降低了前轮侧滑系数, 还明显减小了飞机转弯半径。这表明在设计多支柱飞机的起落架系统时, 应综合考虑前排和后排主起落架的协同作用, 以优化转弯性能。文中研究为多支柱飞机起落架系统的设计和优化提供了理论依据, 有助于提高飞机的转弯性能, 降低飞机转弯过程中的风险, 提高机场运行效率。