飞机滑行状态下振动频率响应分析

发布时间：2018-03-07 14:08

本文选题：机场　切入点：水泥混凝土道面　出处：《中国民航大学》2014年硕士论文　论文类型：学位论文

【摘要】：民用飞机在起飞和滑跑的过程中，由于道面不平度等因素的影响会对道面产生较大的冲击从而使场道整体产生较强的振动，而这一系列振动信号反映了场道的动力响应和承载力水平。本文在国家自然科学基金的大力资助下，依托国家超级计算机天津中心和安世亚太公司对仿真计算的支持。通过理论分析、MATLAB计算和有限元模拟相结合的方法，系统分析飞机滑行过程中对道面结构的力学行为及其激发的振动频率响应。研究结果为场道的优化设计和承载力评价提供了的理论依据。具体工作内容和成果如下： 1、对比分析了各类道面不平度激励模型，建立了国际不平度指数和功率谱密度的换算关系，完成了基于三角级数合成法并与道面不平度评价指标相对应的道面不平度仿真分析。 2、结合时变动力学和振动理论的有关内容，建立了考虑道面的不平度、飞机滑行速度、飞机升力及起落架构型等因素影响的飞机—道面振动系统物理模型及动力学方程，此方程可用于仿真分析道面随机荷载的激励特性。 3、基于仿真生成的道面不平度，研究了飞机滑行过程中对道面的随机荷载，并将这一系列随机荷载施加于有限元模型上，模拟飞机移动荷载的作用过程。这种处理方式能够使飞机—道面系统的振动响应更接近实际工况，提高了模型的精确性。 4、计算分析了飞机移动荷载作用下，道面远端观测点的动位移、加速度、动应力和动应变时程曲线；同时建立了移动荷载作用于不同位置时，各动力响应参数随深度的变化曲线并分析其变化规律。初步确定了道面各结构层的动力响应特点，为场道工程的设计和维护提供了一定的理论依据。 5、通过对道面结构施加激励荷载，提取模型的振动信号，，借助MATLAB获得频谱曲线；同时运用控制变量法，系统分析了结构层参数对道面结构频率以及起落架构型对频谱曲线的影响。结果显示：纵向信号分布呈由高频向低频过渡的特征，且频幅曲线的幅值随深度不断减小；土基厚度和土基模量是道面频率的主要影响因素；起落架构型通过影响荷载的分配形式进而影响激励作用的叠加效果和频谱曲线基频幅值。 6、提出了不停航条件下基于场道振动响应的道面承载力无损检测方案，将该检测技术应用于云南某机场，验证了检测手段与理论成果的可行性，取得了较好的工程实效。
[Abstract]:In the process of take-off and taxiing of civil aircraft, due to the influence of road surface irregularity and other factors, there will be a greater impact on the road surface, which will make the whole field road produce stronger vibration. This series of vibration signals reflect the dynamic response and bearing capacity of the field. Relying on the support of the National Supercomputer Tianjin Center and Anshi Asia Pacific Company to the simulation calculation. Through the theoretical analysis of MATLAB calculation and finite element simulation method, The mechanical behavior of the pavement structure and its vibration frequency response are systematically analyzed. The results provide a theoretical basis for the optimal design of the field track and the evaluation of the bearing capacity. The specific work contents and results are as follows:. 1. The excitation models of various pavement roughness are compared and analyzed, and the conversion relationship between the international roughness index and the power spectral density is established, and the simulation analysis of the pavement roughness is completed based on the triangle series synthesis method and corresponding to the pavement roughness evaluation index. 2. Combined with the related contents of time-varying dynamics and vibration theory, the physical model and dynamic equation of the aircraft-track surface vibration system are established, which take into account the factors such as the roughness of the track surface, the flight speed, the lift force of the aircraft and the configuration of the landing gear, and so on. This equation can be used to simulate and analyze the excitation characteristics of random loads on the pavement. 3. Based on the unevenness of the track surface generated by simulation, the random loads on the pavement in the course of aircraft taxiing are studied, and a series of random loads are applied to the finite element model. This method can make the vibration response of the aircraft-pavement system closer to the actual working conditions and improve the accuracy of the model. 4. The dynamic displacement, acceleration, dynamic stress and dynamic strain curves of the observation point at the far end of the track surface under the moving load of the aircraft are calculated and analyzed, and the moving loads acting on different positions are also established. The dynamic response curve of each dynamic response parameter with depth is analyzed, and the dynamic response characteristics of each structure layer on the pavement surface are preliminarily determined, which provides a certain theoretical basis for the design and maintenance of the field track engineering. 5. By applying the excitation load to the pavement structure, the vibration signal of the model is extracted, and the spectrum curve is obtained by the aid of MATLAB, and the control variable method is used at the same time. The influence of structural layer parameters on the frequency of the pavement structure and the landing gear configuration on the spectrum curve is systematically analyzed. The results show that the longitudinal signal distribution is characterized by the transition from high frequency to low frequency, and the amplitude of the frequency amplitude curve decreases with the depth. The thickness of soil foundation and the modulus of soil foundation are the main factors affecting the frequency of the pavement, and the landing gear configuration affects the superposition effect of excitation and the fundamental frequency amplitude of the spectrum curve by influencing the distribution of load. 6. The nondestructive testing scheme of the pavement bearing capacity based on the vibration response of the track is put forward under the condition of no stopping the navigation. The detection technology is applied to a certain airport in Yunnan province, and the feasibility of the testing method and the theoretical results are verified, and good engineering results are obtained.
【学位授予单位】：中国民航大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.2;V351.11

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