执行GB 50157-2003《地铁设计规范》部分条文的体会和建议

通过学习、执行GB 50157—2003《地铁设计规范》,并结合地铁工程实践,介绍了对该标准中部分章节如钢轨选型、轨底坡设置、交叉渡线和单渡线的线间距设置以及辅助线道岔铺设等内容的一些体会,并提出了相应的建议。     

轨道不平顺导致的车桥耦合振动分析

研究目的：轨道不平顺常常是激起车桥系统耦合振动的主要因素之一，通过研究轨道不平顺导致的车桥耦合振动规律，为铁路桥梁精确设计提供理论依据。 研究方法：以H．Hamid等人提出的轨道不平顺功率谱密度为例，构造了时域内的轨道随机不平顺函数。以轨道不平顺样本函数为激振源，通过求解车桥系统耦合振动微分方程，分析铁路桥梁在列车荷载作用下的动力响应规律。 研究结果：计算了广西红水河铁路斜拉桥在列车通过时的动力响应，给出了不同车速及不同不平顺样本函数情况下桥梁主跨中点横向位移时程曲线。 研究结论：桥梁结构动力响应主要随车速及不平顺样本函数的不同而变化，且有较大的随机性。对于广西红水河铁路斜拉桥，桥梁主跨中点的最大横向位移一般在车速为75～95km／h时达到最大。     

将田径训练渗透在篮球教学中的可行性研究

本文通过在高职院校体育篮球选修班中,进行渗透式田径训练的教学手段,旨在重新确立田径运动的终身健身价值,使之成为大学生终身受益的健身方式之一,使田径运动以全新的面貌进入高校体育健康课程体系。     

船用微型锅炉非线性温度系统控制器仿真与研究

为了实现对船用微型锅炉高、低水温的控制，在Matlab环境下对实测和计算的数据进行曲线拟合，建立了船用微型锅炉水温系统的非线性数学模型。运用滑模变结构控制理论，选取线性切换面和比例型趋近率，设计了一种滑模控制器，实现了双输入双输出非线性耦合温度系统的解耦和控制。通过Matlab／Simulink软件的仿真，结果显示滑模变结构控制算法对非线性系统的控制有响应快、超调小、调节时间短、无误差和抖动的特点。     

牵引-焊接双工况变流器的研制

提出了一种焊轨车用的牵引．焊接双工况变流器，该变流器用一套主电路和控制单元来满足焊轨车的牵引与焊接两种工况需求，可为焊轨车提供走行动力与焊接作业电源，解决了焊接工况下柴油发电机组三相负载不平衡与容量浪费的问题。详细介绍了该变流器的工作原理、主要技术参数、研究与开发过程。     

A rail roughness growth model for a wheelset with non-steady,non-Hertzian contact

This paper presents a model simulating rail roughness growth in which the interaction of a wheelset with the track is considered. The aim is to investigate any possible mechanism for roughness growth due to the coupling between the vertical dynamics, the torsional vibration across the axle of the wheelset and the non-steady contact mechanics. The time-domain simulations are carried out for a driven wheelset on tangent track. Both rigid and flexible are considered with parameter variations for moments of the wheelset, vehicle speeds and wavelengths of initial roughnesses. The 2D non-Hertzian and non-steady contact model used in simulations are based on influence coefficients obtained from a boundary element model. The nonlinear development of the rail roughnesses after millions of wheelset passages is also presented.     

A modified integral sliding mode control to lateral stabilisation of 4-wheel independent drive electric vehicles

This paper presents a novel sliding mode controller (SMC) and its application in the lateral stability control of a 4-wheel independent drive electric vehicle. The structure of the SMC is modified and online-tuned to ensure vehicle system stability, and to track the desired vehicle motion references when an in-wheel motor fault happens. The proposed controller is faster, more accurate, more robust, and with smaller chattering than common SMCs chatter. The effectiveness of the introduced approach is investigated through conducted simulations in the CARSIM and MATLAB software environments.     

无缝线路应力放散均匀性控制

简要介绍了应力放散原理,重点阐述了应力放散施工流程,造成应力放散不均匀的一些原因,以及施工中如何更合理、完善地控制应力放散的均匀性。     

On vehicle/track impact at connection between a floating slab and ballasted track and floating slab track's effectiveness of force isolation

When a vehicle runs over the connection between a floating slab track (FST) and ballasted track, wheel/rail impact may occur because of the stiffness difference in the two kinds of track, and thus a transition sector is usually included at the connection to smoothen the stiffness change. This phenomenon is studied by numerical simulation using a time-domain model for an idealised case without such a transition to determine whether it is actually necessary. Calculation results show that the wheel/rail impact load is moderate for a light FST and increases with the vehicle speed or decreasing the natural frequency of the FST. From simulation the wheel/rail parametric excitation is observed, as a result of variation in the stiffness of the FST with the period of the single slab length. The wheel/rail load due to the parametric excitation also increases with the vehicle speed. In addition, good performance of vibration isolation can be seen for the FST in terms of the force transmitted to the infrastructure.     

Estimation of wheel–rail friction for vehicle certification

In certification of new rail vehicles with respect to running characteristics, a wide variety of operating conditions needs to be considered. However, in associated test runs the wheel–rail friction condition is difficult to handle because the friction coefficient needs to be fairly high and the friction is also generally hard to assess. This is an issue that has been studied in the European project DynoTRAIN and part of the results is presented in this paper. More specifically, an algorithm for estimating the wheel–rail friction coefficient at vehicle certification tests is proposed. Owing to lack of some measurement results, the algorithm here is evaluated in a simulation environment which is also an important step towards practical implementation. A quality measure of the friction estimate is suggested in terms of estimated wheel–rail spin and total creep. It is concluded that, tentatively, the total creep should exceed 0.006 and the spin should be less than 1.0 m^?1 for the algorithm to give a good friction estimate. Sensitivity analysis is carried out to imitate measurement errors, but should be expanded in further work.