桥建合一玻璃幕墙结构动力特性仿真分析

高速铁路客运站房大型幕墙是一种桥建合一的结构体系,由于玻璃幕墙体系与列车轨道梁紧密相联,高速列车通过时可能引起玻璃幕墙共振的问题。因此,在设计幕墙结构体系时,行车振动对玻璃幕墙结构体系的影响必须予以考虑。以某高速铁路站房玻璃幕墙结构为研究对象,运用有限元方法进行数值动力仿真分析,分析结果表明:行车振动荷载不会使幕墙结构产生共振;双边列车通行相比单边列车通行,幕墙结构产生的平面外振动位移要大;当行车振动荷载激振方式为竖向力激振时,竖向激振荷载作用下幕墙结构的平面外振动位移很小。     

西宁站站房大跨拱型桁架高空滑移技术研究

为了满足施工进度和吊装空间要求,西宁火车站屋面大跨拱型桁架采用高空滑移法安装。高空滑移法作为大跨度空间钢结构常用的施工技术具有施工作业面小、吊装就位准确性高、结构成型质量高等综合技术优势。但屋盖结构在整体滑移过程中结构的边界条件、荷载状态、内力分布均时刻发生着变化,且影响因素相互关联,因此需要对屋盖结构高空滑移的全过程进行计算分析。设计中利用有限元软件建立结构整体有限元模型,对西宁站站房屋面大跨度钢桁架在累积滑移施工过程进行全过程模拟分析,对屋面桁架和滑移过程中的支撑胎架的受力和变形进行全程监控和验算。     

提速道岔控制设备故障诊断仪转辙机模拟模块的设计

目前国内新建铁路及客运专线多设计为提速道岔,采用三相五线制交流转辙机,在道岔故障维修时,根据流程,逐步排查,过程耗时耗力。针对提速道岔室内道岔控制电路故障维修,设计转辙机模拟模块。模块现场代替室外道岔动作电路部分,与室内控制电路部分相连接,在模拟转辙机动作过程中,采集分析三相电流及电压等数据,智能判断室内道岔控制电路的在线工作状态。所采集数据经模块处理并通过通信上传至上位机,进行数据模拟,信号维修员可据此对室内道岔控制电路工作状态进行人工判断。使用此设备在道岔室内线路故障维修时准确、便捷,减少工作量,节约劳动成本。     

甬江铁路斜拉桥索塔塔梁同异步施工方法对比分析

甬江特大桥为国内首座铁路大跨度钢箱混合梁斜拉桥,钻石形索塔高177.91 m。通过建立索塔与下横梁同、异步施工有限元模型,模拟分析同、异步施工对索塔受力状态及线形的影响。对比分析表明,同、异步施工的索塔受力及线形略有差异,均能满足设计要求,而异步施工较同步在工期上有较大优势。根据对比分析及南岸索塔工期滞后的实际情况,甬江特大桥南北岸索塔分别采用了塔梁异步与塔梁同步的施工方法,最后实现工期的同步,收到了良好的经济与社会效益。     

铁路运输安全虚拟现实模拟培训系统研究

安全是铁路运输的生命线,而人是其中最重要的因素.应用目前的计算机技术、信息及网络技术,采用虚拟现实(VirtualReality,以下简称VR)的方法,对铁路运输现场作业人员进行模拟培训和考核,具有逼真、有效、经济、快速等特点和重要的实用价值.     

铁路智能信号模拟箱的开发和研究

利用ATMEL新一代单片机AT90S2313开发的铁路智能信号模拟箱,不但可以配合全电子化执行机系统的现场调试工作与联锁实验,而且同样适用于电气集中系统.电路设计简单,使用方便,相对于传统的铁路信号模拟设备提高了可靠性和通用性,有一定的发展前景.     

An analysis of internal transit systems requirements for central cities

The deficient performance of existing downtown transit distribution systems may significantly affect the overall performance of the urban transportation system in many metropolitan areas. This paper has two principal objectives. First, it describes an approach entitled Performance Requirements Analysis for developing a set of requirements or standards that a downtown transit system should satisfy and structuring these requirements so as to generate a small set of alternative generic systems for detailed evaluation. Second, it provides a preliminary assessment of performance requirements for distribution systems in 19 of the largest cities in the United States.     

船用柴油机三维装配工艺可视化技术

针对船用柴油机装配具有复杂性的特点，装配工人按照纸质的装配工艺规程和二维装配示意图进行装配不直观的缺点，开发了船用柴油机三维装配工艺可视化系统。通过三维工艺仿真技术、基于MBD的三维信息定义技术、基于XML的工艺信息结构化表达技术，实现了装配信息的可视化表达；通过对teamcenter的二次开发，实现了装配工艺的可视化发布。最后以某船用柴油机中的典型安装工序机架正时齿轮端的中间齿轮安装为对象，验证了三维装配工艺可视化系统的有效性。该系统能够有效地提高装配工艺的直观性，提高工人的装配效率和准确度。     

AN APPROACH TO THE ECONOMIC APPRAISAL OF AVCS MAGLEV

The purpose of an economic appraisal of a transportation project is to help select an efficient transportation investment plan. Here, efficiency means achieving the best transportation service from a given investment and the generation of net benefits at least as great as the costs of the investment. In this article, three future transportation investment alternatives in the USA are compared using the benefit-cost ratio method to illustrate the economic desirability of the AVCS Maglev alternative – an advanced vehicle control system based on magnetic levitation and propulsion. For the completeness of the economic appraisal and the provision of a guide to performing non-user benefit analysis for this promising ITS technology, the socioeconomic effects of implementing AVCS Maglev in the USA are evaluated based on the US National Development Model (NDM).     

Parking Spaces Repurchase Strategy Design via Simulation Optimization

Because of the rapid increase of vehicle numbers and land values, there is an increasing shortage in the supply of parking facilities in many cities. In many parking lots, residential drivers bought private parking spaces with high prices to ensure that they have spaces to park at any time. Recently, some parking lot operation companies plan to temporally repurchase a few private parking spaces back during certain time periods in a day and sell these places to public users to fully utilize the limited parking resources. How to choose the repurchase amounts and stopping time so as to maximize the profit then becomes an important problem. To solve this problem, a Gaussian mixture model is first proposed in this article to describe the time-varying arriving/departing behaviors of drivers and meanwhile the stochastic constraints of the profit maximization problem. Then, the expected optimal repurchase amounts and stopping time are estimated via simulation optimization. This new approach not only provides a useful statistical tool for parking spaces modeling but also overcomes several key limitations of current queuing based methodologies. Particularly, it emphasizes how to model drivers' behaviors on a small time-scale and explains the resulting benefits.