【作者】 李福海；

【导师】 顾宏斌；

【作者基本信息】 南京航空航天大学 ， 载运工具运用工程， 2016， 博士

【摘要】 安全是民航永恒的主题,是民航赖以生存和发展的基础。地面安全作为航空安全重要组成部分,始终是行业监管的工作重点。飞机在地面牵引、停放过程中,由于天气、环境、突发意外事件、人为失误等因素可能会造成人员伤亡或财产损失的地面事故。这些事故虽不像空难事故那样损失惨重、影响巨大,但其发生频率之高,因此同样应该引起足够的警惕和重视。有鉴于此,本文针对航空地面安全,研究探讨常规工况下飞机地面牵引移动过程中和地面停放时的安全问题。主要研究内容包括:1)基于Adams仿真平台,针对B737-800飞机建立了飞机牵引系统的动力学仿真模型,考虑了实际牵引系统存在的连接间隙引起的接触碰撞,对牵引飞机经过地面凹坑和凸起此类不平坦路面产生的牵引载荷及起落架部件受载进行了仿真分析,并考察了不同牵引速度产生的影响;对不同刹车制动力对牵引载荷的影响进行了分析。讨论了不匹配牵引系统对载荷的影响,分析了B737-800飞机前起落架下阻力臂在牵引载荷作用下的失效型式。2)针对现行牵引作业中牵引载荷无法控制,遇到特殊情况或非正常作业时无法保证安全的问题,提出对牵引载荷实施控制以提高牵引作业安全性的思想并设计了一种新型牵引杆,基于半主动式和被动式两类控制方法,该牵引杆可根据需要实时改变自身刚度和阻尼。对确定缓冲参数进行了研究,建立了相关数学模型,通过仿真对可控缓冲特性牵引杆的应用效果进行评估,结果表明,这种新型牵引杆可有效减缓飞机地面牵引载荷。3)在广泛调研飞机制造商(波音和空客)、轮挡制造商、国内外航空公司及机场的基础上,通过分析B737-800飞机试验等相关资料,完成了飞机的前风升力、前风推力及侧风推力计算,通过对飞机进行受力分析得出了轮胎载荷分布情况;以国内常见橡胶轮挡和金属轮档为例,结合风力环境、地面环境、刹车状态、极限风速,利用摩擦锥自锁原理详细分析了在飞机依靠轮挡所能克服的最大风速条件下轮挡的阻挡功效和可能失效形式。4)利用有限元方法对2种金属轮档进行分析,提出了参量“推开系数”来衡量金属轮挡的阻挡功效,比较得出了它们的优缺点,并对金属轮挡进行了拓扑优化;在综合考虑轮挡阻挡功效、结构失效、使用便利性等各种因素后,提出了优化的橡胶轮挡设计方案和综合性能较高的金属轮挡设计方案。更多还原

【Abstract】 Aviation safety is an everlasting subject of civil aviation and the basis of the civil aviation’s survival and development.As an important part of aviation safety,the aircraft ground safety is always the focus of govermental supervision.When airplanes are parking or being towed,bad weather,environment,unexpected events,human error and other factors may cause ground accidents with casualties and property loss.Although the results of these accidents are not as serious as results of fatal aircraft crashes and the impacts of these accidents are not very huge,the frequency of these accidents is so high that they should be paid enough attention.In view of this,this paper is to study the safety of aircraft ground traction process and ground parking under normal operating conditions.The main research contents include:1)Based on the Adams simulation platform,the dynamic simulation model of the aircraft traction system was established,and the traction loads and the landing gear parts of the traction system were analyzed by simulating.The influence of the non-matching traction system on the load was analyzed,and meanwhile the failure mode of the drag arm under the action of the load on the front landing gear of the B737-800 airplanes was analyzed.2)In order to improve the present situation that towing loads are uncontrollable and safety can not been maintained in special conditions or under non-normal operation,the idea of controlling the towing loads was proposed and a new type towbar with controllable shock absorption was developed.On the basis of active or passive controlling means,the towbar can change its oneself stiffness and damping in real time.After the completion of the relevant parameters,the new type towbar was simulated and the results showed that this new type of towbar could effectively reduce the towing overloads.3)Based on the investigation for the aircraft manufacturers including Boeing and Airbus,wheel chock manufacturers,airlines and airports in China and abroad,the formulae of the forward lift,forward thrust and cross thrust of wind were set up according to the test data of B737-800 airplanes on the ground,and the load distribution to aircraft tires were gotten by analyzing the forces on aircraft and calculating the gravity center of aircraft.In consideration of wind forces,ground conditions,brake status and maximum wind speed permitted,the restraint efficacy and the failure modes of rubber and medal chocks popularly used in China have been thoroughly studied by using the self-clocking principle of friction cone when the airplanes can be restrainted by chocks under extremely high wind conditions.4)The finite element method was used to analyze the two kinds of metal chocks,and the new parameter of “coefficient of pushing away” was put forward to measure restraint efficacy of wheel chocks.The advantages and disadvantages of the two metal chocks were compared and the topological optimization of metal chocks was also carried.In addition,the paper put forward the optimized design schemes for rubber and metal chocks with high comprehensive performances according to the restraint efficacy and failure modes and convenience to use.更多还原