大跨度混合梁斜拉桥上无砟轨道纵向力分析

以昌赣客运专线(35+40+60+300+60+40+35)m混合梁斜拉桥为例,建立了大跨度斜拉桥上无砟轨道精细化模型计算分析不同荷载作用下大跨度桥上无砟轨道纵向力。计算结果表明:在温度荷载作用下,钢轨纵向应力相对较大,最大拉应力为130.03 MPa,跨中轨道板纵向应力较小。在竖向荷载作用下,钢轨、轨道板和底座板的拉应力最大值出现在桥塔附近,压应力最大值出现在跨中附近,其中钢轨压应力最大值为15.02 MPa,底座板拉应力最大值为3.05 MPa。在列车制动作用下,钢轨、轨道板和底座板的拉应力最大值出现在跨中附近,压应力最大值出现在桥塔附近,轨道板和底座板纵向应力均较小。     

地铁列车过渡车钩功能改进及应用

针对目前内燃调车机车采用过渡车钩对地铁列车调车作业中存在的问题,提出了对过渡车钩的改进方案,以达到缓解地铁列车停放制动、提高调车效率的目的。同时提出了对地铁列车制动管路进行改进的思路,以实现内燃调车机车与地铁列车同步实施制动与缓解,从而大幅提高调车过程的安全性与效率。     

高速铁路枢纽站技术作业计划与动车所调车作业计划协同编制研究

分析高速铁路枢纽站技术作业计划与动车所调车作业计划的协同编制过程,提出了将两个计划一体化编制的思想。以需安排作业效益最大化为优化目标,构建基于动车组车底的高速铁路枢纽站与动车所作业计划协同编制模型。针对模型特点,提出瓶颈工序、启发式分配规则及粗粒度主从进程模式的并行禁忌搜索策略(PTS)相结合的混合优化算法,首先确定作业安排瓶颈工序,然后启动主进程和若干从进程,主进程运用启发式分配规则快速生成初始解分配给从进程,从进程运用与瓶颈工序相关的禁忌算法搜索优化解,并反馈给主进程,主进程记录全局最优解并根据交叉策略生成新的初始解,重新分配给从进程进行TS搜索。最后,用实例验证了模型和算法的有效性。     

超长重载列车纵向力影响规律仿真研究

建立超长重载列车纵向动力学仿真模型,并利用大秦线3万t重载组合列车长大下坡道制动试验数据对其进行验证;分析超长重载列车平直道制动工况时列车编组长度、机车无线同步控制延迟时间,以及长大下坡道常用全制动时坡度差、车钩间隙和ECP制动控制技术对纵向力的影响规律.结果表明:正常情况下,4万～12万t超长重载组合列车编组长度对平...     

A proposal for cost-related and market-oriented train running charges

This paper examines some key aspects of a charging system for promoting railway transport, including charges reflecting a clear relationship with costs (transparency) and charges reflecting the quality of the infrastructure manager's service. Train running charges recover track-related costs and can help to develop a charging system that meets these requirements. To orient train running charges to the market, a method for processing track maintenance and renewal costs is proposed whereby the quality of the service provided by an infrastructure is measured according to its utility to the railway undertaking. To achieve transparency, a single indicator is used for cost planning and the subsequent levying of costs on railway undertakings. The paper includes an example of how proposed train running charges would be calculated according to data from 14 European countries. The example shows that short-distance trains generate the lowest maintenance and renewal costs, followed by long-distance trains and freight trains.     

某车型座椅骨架动态安全性与模态分析

为判断汽车座椅骨架的结构合理性,文章利用ANSA建立了某乘用车座椅骨架总成及假头型有限元模型,对该座椅骨架进行了模态分析与基于显式动力学有限元的头枕吸能性仿真试验,得到前四阶固有频率和振型、头枕前碰仿真分析加速度时间历程图。结果表明,该座椅骨架自由模态频率避开了人体最敏感的共振频率范围,整个碰撞过程假头型减速度超过80 g的连续作用时间未超过3 ms。     

城市轨道车辆节能运行方式的研究

本文通过对完成两站之间牵引任务能耗的分析和对城市轨道车辆运行方式的分析,找出了影响能耗的关键,得出了在城市站距较短的条件下快速轨道电车的最佳运行方式.最后讨论影响能耗主要参数选择的一些考虑.     

高速列车侧风安全域计算方法

使用参数传递、求解控制以及动态网格技术, 建立了侧风流体动力学模型和高速列车多体动力学模型, 通过对列车外流场和系统响应进行协同仿真, 获得不同侧风环境下列车的稳定姿态和气动载荷, 研究了列车运行的安全性指标, 分析了不同侧风环境下列车安全运行的临界速度, 确定了列车的侧风作用安全域。计算结果表明: 随着列车运行速度和侧风强度的增大, 轮重减载率、脱轨系数和轮轴横向力依次出现超限现象; 当列车运行速度小于300 km·h^-1时, 列车头车所有轮对均逆风向偏移; 当列车运行速度为300 km·h^-1且侧风风速为30 m·s^-1以及列车运行速度为350 km·h^-1且侧风风速不小于25 m·s^-1时, 一、二位轮对顺风偏移, 三、四位轮对逆风偏移; 列车运行速度越高, 抵抗侧风能力越低, 且列车临界速度对侧风强度的敏感性增大。     

基于船舶油料管理中船舶油耗的研究

鉴于目前船用燃油价格高居不下、船舶油耗费用占船舶运营费用比重较大的实际情况,本文针对船舶的加油及油耗管理工作进行深入研究,对降低航运企业的燃油成本、控制船舶运营费用的工作具有一定的指导意义。     

A bintree energy approach for colour image segmentation using adaptive channel selection

A new hierarchical approach called bintree energy segmentation was presented for color image segmentation. The image features are extracted by adaptive clustering on multi-channel data at each level and used as the criteria to dynamically select the best chromatic channel, where the segmentation is carried out. In this approach, an extended direct energy computation method based on the Chan-Vese model was proposed to segment the selected channel, and the segmentation outputs are then fused with other channels into new images, from which a new channel with better features is selected for the second round segmentation. This procedure is repeated until the preset condition is met. Finally, a binary segmentation tree is formed, in which each leaf represents a class of objects with a distinctive color. To facilitate the data organization, image background is employed in segmentation and channels fusion. The bintree energy segmentation exploits color information involved in all channels data and tries to optimize the global segmentation result by choosing the ＂best＂ channel for segmentation at each level. The experiments show that the method is effective in speed, accuracy and flexibility.