机场道面工程二灰碎石施工

介绍了某民航机场道面工程二灰碎石基层的原材料要求、拌和和摊铺、碾压以及养生、质量检测和施工注意问题等各个方面的具体情况.     

独立旋转车轮系统特点及应用前景

概述了独立旋转车轮系统的特点和目前世界各国采用的几种研究方法及其对应的结构形式，并阐述了其在高速机车车辆和城市轨道车辆上的应用前景。     

提高碎石加工质量的有效方法

针对中国目前高速公路碎石生产存在的加工方式落后、粒径普遍偏大、针片状含量超标、颗粒组成变异性大等问题,根据国内外公路施工的经验,提出提高碎石加工质量的几点意见.     

Fundamental formulation for frictional contact with graded materials

In the paper, we develop the fundamental solutions for a graded half-plane subjected to concentrated forces acting perpendicularly and parallel to the surface. In the solutions, Young's modulus is assumed to vary in the form of E(y) = E0e(ay) and Poisson's ratio is assumed to be constant. On the basis of the fundamental solutions, the singular integral equations are formulated for the unknown traction distributions with Green's function method. From the fundamental integral equations, a series of integral equations for special cases may be deduced corresponding to practical contact situations. The validity of the fundamental solutions and the integral equations is demonstrated with the degenerate solutions and two typical numerical examples.     

减速顶壳体螺栓发生折断故障原因分析及应对措施

通过对减速顶壳体螺栓折断故障进行调查统计，从理论和实际两个方面，详细分析了壳体螺栓折断故障发生的原因及教训，并结合减速顶的结构特点和运行工况，阐述了防范壳体螺栓折断故障的方法和措施，提出了改进下一步工作的意见和建议。     

级配碎石重复加载动三轴试验仿真研究

为减少级配碎石重复加载动三轴试验量,采用Morh-Coulomb塑性模型,对级配碎石重复加载动三轴试验进行了有限元仿真,并对仿真结果用Pérez永久变形预估模型进行了拟合。结果表明:重复加载试验与其有限元仿真得到的永久变形发展规律相同,对仿真结果进行修正后,可用有限元仿真来代替部分室内重复加载试验。     

选择性输出双离合自动变速器液压控制系统设计

液压控制系统是变速器的重要组成部分,油路和阀的设计选择对变速器的动力传递和换挡实现有很大影响。分析了自动变速器液压系统的控制原理,并结合一种新型结构变速器,设计其液压控制系统来满足其换挡和动力传递需要。     

基于电子风扇控制的混合动力客车散热器面积计算

混合动力客车配置电子风扇是发展趋势,但电子风扇的转速、扇叶直径、整车电流对冷却效果有较大影响。用传统方法匹配散热器,很难满足发动机的冷却需要。本文提出一种针对于电子风扇控制冷却的散热器散热面积计算方法。     

Dynamic Train-Track Interaction: Variability Attributable to Scatter in the Track Properties

A numerical method to simulate vertical dynamic interaction between a rolling train and a railway track has been used to investigate the influence of stochastic properties of the track structure. A perturbation technique has been used to investigate the influence of the scatter in selected track properties. The train-track interaction problem has been numerically solved by use of an extended state-space vector approach in conjunction with a complex modal superposition for the whole track structure. All numerical simulations have been carried out in the time-domain with a moving mass model. Properties such as rail pad stiffness, ballast stiffness, dynamic ballast-subgrade mass and sleeper spacing have been studied. To obtain sufficient statistical information from track structures, full-scale measurements in the field and laboratory measurements have been carried out. The influence of scatter in the track properties on the maximum contact force between the rail and the wheel, the maximum magnitude of the vertical wheelset acceleration, and the maximum sleeper displacement have been studied. Mean values and standard deviations of these quantities have been calculated. The effects of the variation of the investigated track properties are discussed.     

沥青稳定碎石基层对沥青路面力学的特性影响分析

沥青稳定碎石基层可以显著减少沥青路面一些早期损害,通过采用ABAQUS三维有限元方法,对设置沥青稳定碎石基层的沥青路面结构进行力学性能分析,分析路面结构应力和应变的影响。从结构角度提出对沥青稳定碎石基层材料的性能的要求,并且对设置排水基层的半刚性基层沥青路面结构设计提出相应建议。