Sensitivity analysis to assess the influence of the inertial properties of railway vehicle bodies on the vehicle's dynamic behaviour

A sensitivity analysis has been performed to assess the influence of the inertial properties of railway vehicles on their dynamic behaviour. To do this, 216 dynamic simulations were performed modifying, one at a time, the masses, moments of inertia and heights of the centre of gravity of the carbody, the bogie and the wheelset. Three values were assigned to each parameter, corresponding to the percentiles 10, 50 and 90 of a data set stored in a database of railway vehicles. After processing the results of these simulations, the analysed parameters were sorted by increasing influence. It was also found which of these parameters could be estimated with a lesser degree of accuracy for future simulations without appreciably affecting the simulation results. In general terms, it was concluded that the most sensitive inertial properties are the mass and the vertical moment of inertia, and the least sensitive ones the longitudinal and lateral moments of inertia.     

基于PPC、PLC及现场总线的铁路大型养路机械电气控制系统

简要介绍了PPC、PIE、现场总线的特点及应用；详细介绍了铁路大型养路机械电气控制系统的现状及系统要求；以新型稳定电气控制系统的设计为例，提出基于PPC、PIE及现场总线的铁路大型养路机械电气控制系统的设计方案。     

到发线有效长度及信号系统适用性分析

对我国普速铁路、高速铁路、时速200 km客货共线铁路、城际铁路和动车段(所)的到发线或存车线有效长度,从标准规范和信号系统适应性两个角度进行分析。对于机车牵引列车运行线路,结合LKJ停车安全距离的计算,对相关标准规范做出补充建议。对于动车组列车运行线路,结合列控系统停车安全距离和列车过走防护距离的计算,对相关标准规范进行分析,并给出必要的优化设计建议。对于动车段(所),结合出入段(所)方式和是否设置调车应答器组,确定不同情况下的存车线有效长度。     

燃气轮机吊装轨道系统结构强度分析研究

以某船为研究背景,进行了燃气轮机吊装轨道的强度分析研究。首先开展了导轨系统的受力分析,给出了不同类型力载荷的理论计算结果;再利用有限元软件分别建立了导轨的杆梁单元和实体单元三维计算模型;然后确定了10个典型计算步的载荷;经过试算对比两种模型,杆梁单元和实体单元模型相比具有求解速度快,效率高等特点。进而确定了以杆梁单元网格为主要计算模型,实体单元网格为校核计算模型的研究思路。计算结果表明：现有吊装轨道系统的强度满足使用要求,在过渡导轨段是整个导轨系统的薄弱环节,需要进一步优化吊装轨迹或者局部结构加强。     

GPS接收机抗干扰性能分析

针对GPS接收机的干扰方式主要为压制式和欺骗式,在压制式干扰信号影响下,GPS接收机的跟踪状态发生变化,载噪比、伪距和载波相位受到影响,从而使定位精度下降或失锁,分析接收机性能变化的根本原因,提高接收机抗干扰的能力。     

浅议25Hz相敏轨道电路故障处理方法

近年来，25Hz相敏轨道电路故障已成为一个影响铁路运输效率的严重问题。通过对故障总结归类，系统地介绍了25Hz相敏轨道电路故障的处理方法。     

25Hz相敏轨道电路断轨（断线）监督检查方案的探讨

25Hz相敏轨道电路的断轨（断线）监督检查问题长期影响着铁路安全行车。针对25Hz相敏轨道电路的断轨（断线）监督检查问题进行分析、探讨,确定实现断轨（断线）监督检查的技术标准,并提出相应解决方案,实现断轨（断线）监督检查。     

Railway ground vibrations induced by wheel and rail singular defects

Railway local irregularities are a growing source of ground-borne vibration and can cause negative environmental impacts, particularly in urban areas. Therefore, this paper analyses the effect of railway track singular defects (discontinuities) on ground vibration generation and propagation. A vehicle/track/soil numerical railway model is presented, capable of accurately predicting vibration levels. The prediction model is composed of a multibody vehicle model, a flexible track model and a finite/infinite element soil model. Firstly, analysis is undertaken to assess the ability of wheel/rail contact models to accurately simulate the force generation at the wheel/rail contact, in the presence of a singular defect. It is found that, although linear contact models are sufficient for modelling ground vibration on smooth tracks, when singular defects are present higher accuracy wheel/rail models are required. Furthermore, it is found that the variation in wheel/rail force during the singular defect contact depends on the track flexibility, and thus requires a fully coupled vehicle/track/foundation model. Next, a parametric study of ground vibrations generated by singular rail and wheel defects is undertaken. Six shapes of discontinuity are modelled, representing various defect types such as transition zones, switches, crossings, rail joints and wheel flats. The vehicle is modelled as an AM96 train set and it is found that ground vibration levels are highly sensitive to defect height, length and shape.     

振动模态分析在浮置板轨道结构上的应用

随着城市轨道交通在国内的快速发展,列车运营所产生的振动及噪声污染问题将越来越突出。为此,在减振要求特殊地段采用浮置板轨道结构,而轨道结构的减振性能与其固有频率有关,因此需要对轨道结构的动力特性进行更深入的研究。在建立浮置板轨道系统的振动分析模型基础上,对浮置板轨道系统进行模态分析,得到该系统的振动动力特性(固有频率、振型),可为轨道结构的合理设计提供一定的理论依据。     

加强线网规划 突出轨道交通在城市发展中的骨干地位

通过对线网规划在线网形态、线网规模、线路敷设方式、资源共享等方面的阐述 ,提出只有在科学规划指导下建设的轨道交通才能有效解决城市交通问题 ,引导城市良性发展。