线控制相位差概率模型研究

在对现有线控制模型和算法进行分析的基础上提出按照概率思想求解相位差参数的策略。论文确立优化相位差的目标为通过车流在主干道上的停车次数和停车延误最小。建立相位差概率模型时,着重考虑4个影响因素:路段上车流行驶速度不均匀性,主干道上下行流量不均衡现象,相交道路上的转弯车流,短连线上的车辆排队约束。最后,论文用实际算例对建立的模型进行了验证,并对进一步的研究工作给出了建议。     

基于环境激励测试值的润扬悬索桥动力特性分析

桥梁结构自振特性分析是进行地震反应分析及风振分析的理论基础,系统而深入的认识桥梁结构的动力特性是十分重要的。通过以润扬南汊悬索桥为研究对象,分析了对其实施环境随机测试的过程及结果,并根据润扬南汊悬索桥的设计图纸用大型商业有限元软件ANSYS建立了悬索桥的三维有限元模型,对成桥后的动力特性进行计算,并与实测值进行了对比分析,结果比较吻合,为该桥进一步动力分析提供了理论基础。     

用于车道识别的分段切换车道模型

为了使得车道模型既能准确地描述车道形状,又不影响车道识别算法的实时性,提出了一种分段切换车道模型。对近视场区域使用直线模型匹配车道线,对远视场区域则在直线模型和二次曲线模型之间进行切换,以适应有曲率和无曲率道路的识别要求。试验表明,使用分段切换车道模型的车道识别算法能够很好地匹配各种形状道路,并能满足实时性要求。     

单点交叉口信号实时配时模型及蚂蚁算法

以延误时间、停车次数和通行能力作为性能指标，各性能指标的加权系数随交通需求的不同而变化。提出交叉口实时配时，采用一种新型随机搜索思想——蚂蚁优化算法来求解此模型的非线形问题。仿真试验表明，所得结果优于经典方法，降低了交叉口的总延误时间和停车次数，提高了通行能力。     

蝴蝶拱桥的有限元分析及模型试验研究

蝴蝶拱桥是一种新型空间组合拱桥，设计巧妙独特，外型美观。为全面分析其力学行为，建立了空间杆系和板壳有限元分析模型。给出了该桥控制截面在几个主要荷载工况下的变形和应变值；为验证计算理论的合理与准确性，确保该桥的安全与可靠性，进行了1／10模型试验，并将理论计算值与实侧值进行了比较，为该桥的设计与施工提出了有意义的建议。     

超大型群桩基础承载特性离心模型试验研究

通过18根和64根群桩离心模型试验,获得了荷载~沉降关系曲线、桩身轴力分布,研究了在竖向荷载作用下超大型群桩基础的承载变形特性和群桩效应,分析了桩身轴力分布、桩顶荷载分布等变化规律。     

沉管隧道地震响应分析

文章采用田村重四郎和冈本舜三提出的沉埋隧道地震响应分析的数学模型,对南京长江越江隧道(沉管段)方案进行了地震响应的纵向受力分析。分析中采用了隧址处100年超越概率为2%的人工合成地震加速度,考虑了不同管段的联结方式和不同的计算参数,对初步设计中沉管段结构的安全性进行了论证,所提供的数据曾为设计单位所采纳[1]。     

Modelling of wheels and rail discontinuities in dynamic wheel-rail contact analysis

A classification of wheel-rail contact is given. Difference is made between modelling of a running wheel with continuous single-point-contact, as is common practice in wheel-rail contact analysis, and a wheel with transient double- or multi-point-contact, which may occur for rail irregularities with curvatures larger than that of the wheel circumference. It is shown that application of the first model for these irregularities will strongly underestimate the contact forces as it does not describe occurring mechanisms correctly. Further, it is shown that in principle it is not possible to describe the second type of contact fully correct with a lumped wheel model. Both wheel models are formulated mathematically for some basic contact cases. Afterwards, results are applied to a linear track model. Analytical closed-form solutions are found in the frequency domain for arbitrary type of contact and numerically transformed to the time domain. Finally, the necessity is shown to avoid situations where transient multiple-point-contact may occur (like rail joints) in practice.     

Tractor-semitrailer model for vehicles carrying liquids

This article presents a model for solving solid-fluid interactions in vehicles carrying liquids. A tractor-semitrailer model is developed by incorporating suspension systems and tire dynamics. Owing to the solid-fluid interaction, equations of motion for the vehicle system are coupled. To simplify the complicated solution procedure, the coupled equations are solved separately using two different codes. Each code is analyzed separately; but as the parameters of the two codes depend on each other, the codes must be connected at the end of each time step. To determine the dynamic behavior of the system, different braking moments are applied. As the braking moments increase, braking time decreases. However, it turns out that increasing the braking moment to more than a certain level produces no significant results. It is also shown that vehicles carrying fluids need a greater amount of braking moments in comparison to vehicles carrying solids during braking. In addition, as the level of the fluid inside the tanker increases, from one-third to two-third of the tanker's volume, the sloshing forces applied to the tanker's walls increase. It was also concluded that the strategy used in this article to solve for the solid-fluid interaction by incorporating vehicle dynamic effects represents an effective method for determining the dynamic behavior of vehicles carrying fluids in other critical maneuvers.     

提前右转的科学性论证

分析了十字交叉路口直行车流和右转车流产生交通分流冲突的原因,以及因此而造成的交通事故隐患。为解决这个问题,笔者在借鉴国内外交通冲突技术(TCT)的理论研究成果的基础上,建立了十字路口直行车流和右转车流分流冲突模型,并用北京市火神庙十字路口的调查统计数据对模型进行了验证,从而在理论上证明了"提前右转"对于减少交通冲突,提高交叉路口安全的科学性,对于交叉路口设计和改造具有较强的指导意义。