复合材料磁悬浮列车车体结构数值模拟(Ⅱ)——车体结构性能数值模拟试验

以参数化磁悬浮列车车体有限元模型为基础，在各种载荷和边界条件下开展数值模拟试验，研究各种运营环境中车体结构的静力学和动力学性能。在Siemens NX中完成车体在各种典型载荷工况下的结构静力学和动力学性能模拟试验，包括车体结构载荷变形、车体主要连接部件结构力学性能、车体频率及振型、车体结构线性屈曲性能，以及车体动力响应性能等。数值模拟结果认为给定的复合材料磁悬浮列车车体设计可行，同时验证参数化车体有限元模型的有效性。     

岳西县小水电开发思路与具体做法

文章介绍了岳西县小水电开发思路与具体做法。主要是认真编制规划、股份合作融资、优化设计方案、工程公开发包、实行目标管理等。     

Psychological work characteristics,psychological workload and associated psychological and cognitive requirements of train drivers

This study aimed to assess the psychological work characteristics and psychological workload of train drivers and to define the psychological and cognitive requirements of their work. A systematic literature search was performed, and expert interviews were conducted. The following work demands were specific to train drivers: high emotional and mental demands, small amount of autonomy and skill discretion. No evidence of a high emotional workload, a high mental workload or short-term stress reactivity was found. In general, the drivers' fatigue complaints and recovery needs after work were comparable to that of other workers. However, severe sleepiness and high need for recovery did affect a substantial proportion of train drivers. The ability to stay aware, to anticipate, to remain attentive and to cope with fatigue are psychological and cognitive skills that are required to adequately and safely perform the train drivers' job. Including these requirements in periodic assessments of train drivers is recommended.     

Passenger comfort on high-speed trains: effect of tunnel noise on the subjective assessment of pressure variations

When passing through a tunnel, aerodynamic effects on high-speed trains may impair passenger comfort. These variations in atmospheric pressure are accompanied by transient increases in sound pressure level. To date, it is unclear whether the latter influences the perceived discomfort associated with the variations in atmospheric pressure. In a pressure chamber of the DLR-Institute of Aerospace Medicine, 71 participants (M = 28.3 years ± 8.1 SD) rated randomised pressure changes during two conditions according to a crossover design. The pressure changes were presented together with tunnel noise such that the sound pressure level was transiently elevated by either +6 dB (low noise condition) or +12 dB (high noise condition) above background noise level (65 dB(A)). Data were combined with those of a recent study, in which identical pressure changes were presented without tunnel noise (Schwanitz et al., 2013, ‘Pressure Variations on a Train – Where is the Threshold to Railway Passenger Discomfort?’ Applied Ergonomics 44 (2): 200-209). Exposure-response relationships for the combined data set comprising all three noise conditions show that pressure discomfort increases with the magnitude and speed of the pressure changes but decreases with increasing tunnel noise.

Practitioner Summary: In a pressure chamber, we systematically examined how pressure discomfort, as it may be experienced by railway passengers, is affected by the presence of tunnel noise during pressure changes. It is shown that across three conditions (no noise, low noise (+6 dB), high noise (+12 dB)) pressure discomfort decreases with increasing tunnel noise.     

客车水栓压力在线监控系统的应用及推广

针对铁路客车上水栓的现状及特点,设计出一套客车水栓压力在线监测及故障自动切除系统,并分析了使用该系统的必要性,介绍了该系统可实现的功能,对该系统的关键技术及监控组态软件设计作了详细论述,以促进其推广应用。     

Investigation of solar hybrid system with concentrating Fresnel lens,photovoltaic and thermoelectric generators

An experimental model of a solar hybrid system including photovoltaic (PV) module, concentrating Fresnel lens, thermoelectric generator (TEG), and running water heat extracting unit was created and studied. The PV module used was of c‐Si and TEG of Bi₂Te₃; the Fresnel lens (solar concentrator) and TEG share an optical train, whereas PV module was illuminated separately with non‐concentrated light. Heat extracting unit operated in thermo siphon mode. In climatic conditions of Mexico (Queretaro, 20^o of North latitude, summer time), the Fresnel lens accepted 120 W of solar radiation power, and the system generated 7.0 W of electric power and 30 W of thermal one. The discussion is made of the possible characteristics of a hypothetical hybrid system where all its elements share the same optical train. Copyright © 2016 John Wiley & Sons, Ltd.     

A health management algorithm for composite train carbody based on FEM/FBG hybrid method

In this study, a health management program for a composite train carbody was developed using the acquired strain distributions from fiber Bragg grating (FBG) sensor arrays. To determine appropriate locations for the FBG sensors, a finite element analysis (FEA) was executed. In this FEA, a FE model of the Korean tilting train (TTX) was used as a representative composite carbody train. The FEA results of various derailment situations and high speed operation on curved track were used as the database of each deformation case. In the last step, the health management program was produced using LabVIEW software. In this post-processing algorithm, the method of least squares was used to determine the difference between the FEA results and the acquired strains. This program shows the estimated deformations and plots of the acquired strains, as well as displaying an emergency indicator when necessary, all through post-processing of the strains. Finally, this FEM/FBG hybrid method was verified by several simulations using the reproductive sensor data.     

The influence of train properties on railway ground vibrations

This paper uses a sensitivity analysis to quantify the dominant train properties (mass and spacing of wheels and bogies) that contribute to ground-borne vibration generation, with the aim of reducing the complexity of train–track numerical models. This research is significant because ground-borne vibration from railways is a growing problem, particularly in urban areas. Despite this fact, attempting to predict vibration levels is complex because there are many variables that contribute to the overall dynamic response. Therefore, a deterministic approach is commonly used, that ignores many of these variables. Thus, this paper identifies the variables that can be ignored, while highlighting those that are highly influential on vibration generation. For this purpose, a previously validated 2.5D finite elements-boundary elements approach is used to simulate dynamic train–track interaction. It is computed many times for a variety of modelling variables to investigate the effect of each on the ground-borne vibration levels in the far field. It is found that increases in unsprung mass of the train causes a large increase in vibration levels. Furthermore, changes in wheel/bogie spacing and semi-sprung mass are found to have a minimal effect on vibration generation.     

基于扫描激光雷达的列车速度测量系统

针对传统列车速度测量装置存在量程小、调试复杂等问题,基于扫描激光雷达技术,设计了一套适用于高速列车动态限界测量的列车速度测量系统。将扫描激光雷达固定在距列车10m 左右的位置上,根据激光脉冲飞行时间测距原理,沿列车行驶方向对进入扫描范围内的列车车身逐点扫描,获得由测量点组成的车身轮廓信息;通过最小二乘拟合车厢测量点,得到列车行驶轨迹,确定列车行驶方向;采用分段线性差值确定相邻两次测量周期内列车行驶的距离,完成列车速度的测量。结果表明:该测速系统操作方便,量程可达600km/h,测速误差控制在1.2%以内,可以满足高速列车速度测量需求。     

一种应用于列车信息画面实时重建的快速绘图方法

在许多视频应用中,画面重建是一个重要的课题。提出一种应用于列车信息实时分析重建系统的快速绘图方法使用双缓存技术在内存空间申请指定大小的位图,通过图形设备接口在该位图上进行图形绘制。绘图模块对基本绘图单元进行封装,各绘图元素单元具有相似的设置接口。采用了双缓冲技术避免闪烁,同时采用部分绘制方法,提高绘制速度。该绘图模块具有很好的可扩展性、实时性和灵活性。所提出的快速绘图方法在列车信息实时分析重建系统中得到很好的应用。