层次分析法决策优选高铁软基处理方案

目前软土地基的处理方法较多,如何选择合理的处理方式已成为软基施工中的主要问题,运用层次分析法,针对高速铁路软基处理方案优化问题,给出方案优化选择模型,为软基施工的处理方案选择提供依据。     

�г�����ͨ�������ṹ��������·��Ӫ�����о�

以经济性、快速性、便捷性、舒适性及安全性为衡量指标,建立乘客出行广义费用函数;结合非集计理论和方法,构建中长距离通道客流分担率模型.并以武汉—广州客运通道为例,分析不同时间价值下客流结构的变化情况,发现普通铁路更加符合旅客的出行偏好,其客运分担率高于45%.最后,以利润为指标,对高速铁路运营策略进行了分析.研究结果表明,由于普通铁路与高速铁路之间的竞争关系,高速铁路运营利润及铁路总利润难以同时达到最优;当以高速铁路运营利润最大为目标时,高速铁路票价和旅行速度分别为275元和325km/h;当以铁路总利润最大为目标时,高速铁路票价和旅行速度分别为350元和300km/h.     

高速列车气动噪声仿真与试验对比分析

通过Actran建立某高速列车1∶8缩尺比例的三辆编组的列车气动噪声CFD/CAA混合数值分析模型,模拟列车在250 km/h运行速度下外气动湍流噪声,分析结果表明,车外气动噪声在车头、受电弓、转向架处较大,且主要集中在500~2 000 Hz频率范围内.并将仿真分析结果与相应1∶8缩尺比例的列车模型在声学风洞中的气动噪声试验结果数据进行对比分析,仿真数据与试验数据基本吻合,仿真分析结果可以为新车型设计与改进提供可靠的数据.     

基于高速摄影的水下爆炸破片侵彻特性试验

为研究水下爆炸产生高速破片的侵彻特性,采用高速摄影技术对2种典型破片的侵彻过程进行了弹道试验。试验结果表明:冲击和空泡阶段破片侵彻深度随时间迅速增加,拖曳阶段增速逐渐放缓;而在这2个阶段速度衰减很快,到后期低速阶段速度衰减放缓,且其侵彻特性与质量密切相关。冲击和空泡阶段的实际侵彻深度为40~60 cm,这一深度仅相当于破片最终静止时侵深的40%左右,而这一过程却耗散了破片95%以上的初始动能。拖曳阶段破片虽然能在液舱中行进较远的距离,但液舱吸收的破片动能较少。     

Pareto optimisation of railway bogie suspension damping to enhance safety and comfort

This paper presents the optimisation of damping characteristics in bogie suspensions using a multi-objective optimisation methodology. The damping is investigated and optimised in terms of the resulting performances of a railway vehicle with respect to safety, comfort and wear considerations. A complete multi-body system model describing the railway vehicle dynamics is implemented in commercial software Gensys and used in the optimisation. In complementary optimisation analyses, a reduced and linearised model describing the bogie system dynamics is also utilised. Pareto fronts with respect to safety, comfort and wear objectives are obtained, showing the trade-off behaviour between the objectives. Such trade-off curves are of importance, especially in the design of damping functional components. The results demonstrate that the developed methodology can successfully be used for multi-objective investigations of a railway vehicle within models of different levels of complexity. By introducing optimised passive damping elements in the bogie suspensions, both safety and comfort are improved. In particular, it is noted that the use of optimised passive damping elements can allow for higher train speeds. Finally, adaptive strategies for switching damping parameters with respect to different ride conditions are outlined and discussed.     

高速客运专线牵引变压器阻抗电压的选择

从变压器的产品标准、阻抗电压与成本的关系、阻抗电压与电压损失的关系、不同阻抗时变压器电压损失、不同阻抗时的短路电流及其引起的钢轨电位等多个方面论述了高速客运专线牵引变压器阻抗电压的参数选择问题,指出高速客运专线的牵引变压器接线采用单相变压器接线型式宜选为12.5%以上;若非单相变压器接线型式,可取选为12.5%以下.     

焊不透缺陷对某转向架结构强度的影响分析

利用有限元分析软件ANSYS,采用“壳到实体”、“实体到实体”子模型法,以CW-200转向架构架帽筒焊不透缺陷对结构强度的影响进行了分析,得到了焊缝未焊透缺陷对结构强度的影响规律。     

高速电气化铁路接触网施工关键技术

以国内多条高速电气化铁路接触网施工实践经验为依托,研究探讨了高速接触网施工安装中的关键技术,为今后高速铁路接触网施工安装及标准的建立提供借鉴。     

Influence of the transmission configuration of a multiple axle vehicle on the obstacle surmounting capacity

Conventional wheeled vehicles have serious mobility limitations in rough terrain while walking vehicles have inherent drawbacks such as a high number of DOF and actuators, control complexity and low-energy efficiency. Vehicles that passively adapt the position of multiple wheels to maintain contact with the ground can be a good compromise between both conventional wheeled and walking vehicles. One way to increase the number of wheels in contact with the ground is using bogies. However, the kinematics of a multiple axle vehicle moving on irregular terrain is quite complex since every wheel can require different angular speed to avoid slippage. The present work aims to quantify the obstacle surmounting capacity of a four axle, double-bogie vehicle depending on the transmission configuration, since it can provoke the slippage of some of its wheels.

Some results are presented corresponding to the vehicle moving on a straight upward slope of different angles and facing variable obstacles in any of its axles.

It can be observed that as more restricted the transmission is, more wheels are forced to slip and less traction the vehicle has, and, as a consequence, less obstacle surmounting capacity.     

S7-200 PLC高速计数器在电子调速器仿真训练器中的应用

高速计数器的主要功能就是对主机实际转速反馈进行测量,这是电子调速器的一项重要功能,因为主机实际转速反馈测量的准确与否直接关系到保证主机转速稳定,保证主机运行的安全.重点介绍了S7-200PLC高速计数器.在开发研制中发现,采用S7-200 PLC高速计数器可以非常准确地对主机实际转速反馈进行测量,而且硬件实现非常简单,价格也比较低,具有很大的实船应用价值.