军用机场水泥混凝土道面累积疲劳作用的平面分布规律研究

Pavement traffic distribution characteristics has great influence on the concrete pavement by the force of stress distribution and fatigue damage. Pavement traffic distribution are not only transverse distribution of traffic flow, but also has the traffic vertical distribution. In domestic and foreign pavement traffic model is built based on the transverse distribution in traffic, with a great limitations. Using the infrared tracking and video collection system, the airport road face a lot of traffic flow testing, analysis road surface volume of traffic of the plane distribution law, and reconstruction of the existing road face traffic model. On this basis, according to the distribution features of the load of the airport, and discusses pavement cover role superposition principle and cumulative number of fatigue effect, the computation method of longitudinal cumulative fatigue analysis of the factors affecting the role, the pavement accumulated fatigue effect plane distribution law, based on cumulative fatigue effect planar distribution of pavement design methods, foreign latest pavement design method will become its highly channelizing under special case of in traffic. This topic research, will solve different pavement for design method for the calculation of the differences on landing traffic to provide ideas, to reveal the airport pavement cumulative fatigue effect plane distribution has an important meaning, and can be established based on cumulative fatigue effect for the distribution of the plane design method of pavement theoretical foundation. Would be considerably reduced our country in the pavement design and foreign gap, every China to realize the pavement design theory and method of the great-leap-forward development, has the important theoretical significance and application value.

道面交通量分布特性对道面受力应力分布、疲劳损伤具有重要影响，机场道面交通量分布不仅存在交通量横向分布，还存在交通量纵向分布。目前我军现行机场道面设计方法中道面交通量模型都是建立在交通量横向分布基础上，没有考虑交通量纵向分布。本课题以军用机场水泥混凝土道面为研究对象，采用飞机视频跟踪系统，对机场道面交通量进行测试，分析道面交通量的平面分布规律，并重建现有机场道面交通量模型。在此基础上，根据机场飞机荷载的分布特性，探讨道面覆盖作用次数叠加原理与累积疲劳作用的计算方法，分析纵向累积疲劳作用的影响因素，研究道面累积疲劳作用的平面分布规律。本课题的研究，将为研究机场不同区域道面的累积疲劳损伤程度提供依据，为解决不同道面设计方法在着陆交通量计算上的分歧提供思路，揭示机场道面累积疲劳作用的平面分布规律，可为建立基于累积疲劳作用平面分布的道面设计方法奠定理论基础，具有重要理论意义和应用价值。

本课题自主研发了机场道面轮迹平面分布测试系统，对三个军用机场所保障四种机型的飞机轮迹开展四次现场测试，在归纳轮迹横向和纵向分布规律的基础上，构建了机场道面交通量的平面分布模型用以道面任一点的实际通行覆盖作用次数计算。采用大型有限元仿真软件ABAQUS与MATLAB的联合仿真，实现了道面各点应力状态的快速计算，建立了一个可供分析道面累积疲劳作用叠加的九块板的三维有限元模型，并通过现场试验验证了模型的有效性。基于变采样频率的滤波白噪声法，考虑机体的升力、上下颠簸、侧倾运动和俯仰运动，建立了六自由度全机滑跑动力学方程，并采用SIMULINK工具箱对道面平整度和滑跑速度耦合作用下的机轮动载系数进行求解，通过拟合仿真结果给出了道面不平度和滑跑速度耦合作用下机轮动载系数计算公式，得到了起飞着陆全过程道面机轮荷载的纵向分布规律。结合道面机轮荷载的纵向分布和三维有限元模型，分段计算道面各点的应力纵向分布规律，并代入到考虑高低应力比的水泥混凝土疲劳方程，以得道面各点的允许作用次数。实际通行覆盖作用次数与允许作用次数的比值即为道面各点累积损伤因子，按照Miner线性疲劳准则，对单机起飞、双机起飞和着陆三种状态下的累积损伤曲面进行叠加，最终得到了军用机场累积疲劳作用的平面分布规律。本课题的研究，可以解决不同规范起飞着陆交通量损伤换算的分歧，对建立基于累计损伤曲面的机场道面设计方法和道面分段设计奠定理论基础，具有重要的理论意义和应用价值。

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