示功图采集及修正处理方法研究

利用实测示功图对柴油机燃烧过程进行分析,是进行柴油机性能研究的重要手段.针对这一需要,对实测示功图中压力值的修正处理方法进行了研究,并利用MATLAB工具箱对测量信号进行频谱分析,就通道效应对示功图的影响进行了讨论.     

高速公路机电工程自动化辅助设计软件研发及应用

文章首先对国内外设计现状及设计软件研发的现状及必要性进行分析,而后对研发关键技术进行了阐述,并对主要功能应用进行了详述,最后对软件的发展进行了展望。     

关于发展我国智能交通系统的思考

对国内、国际智能交通系统发展现状进行了介绍,对我国智能交通的发展目标进行了概述,并对其发展前景进行了展望.     

智能公交系统设计方案分析研究

该文通过对智能公交系统进行分析,对BRT系统组成元素进行详细分析,并对智能公交系统进行各模块系统设计,对当前智能公交系统设计研究有一定指导意义。     

前保格栅对冷却模块性能影响的仿真与试验分析

利用三维仿真软件,将2种不同格栅在50km/h车速下,对前端冷却模块气流状态的影响进行了模拟,并与风洞试验室进行的整车试验结果进行对标,对仿真模拟的准确性进行验证。在项目前期概念设计阶段,对改型格栅进行性能验证,代替实车对比试验,对整车开发有重要的指导意义。     

箱涵结构优化设计

对混凝土箱涵进行了设计和验算,同时对原箱涵的顶、底板施加预应力,进行了有限元计算,并对原箱涵的顶、底板厚度进行调整减薄,施加直线预应力,进行有限元计算,结果表明:预应力箱涵顶、底板没有出现拉应力.最后进行了锚固区承压计算,结果符合要求.     

宜长高速公路女娘山隧道的修建

对女娘山隧道开挖方法进行比选,并用ANSYS程序对台阶法进行有限元计算,对施工中存在的问题进行了探讨并提出解决办法。     

浅谈轻卡车型匹配前独立悬架系统的研究与运用

本文通过对双摆臂式独立悬架的结构特点进行分,对某轻卡匹配双摆臂式独立悬架系统进行阐述,具体对导向杆系、螺旋弹簧、减振器进行匹配分析计算,同时借助ADAMS进行仿真验证其合理性.     

基于ANSYS的车架形状拓扑优化研究

提出了车架传统设计的不足,利用ANSYS软件,首先对车架进行拓扑优化得到各梁的大致分布位置,再对各横梁进行形状尺寸优化,使得在满足强度要求下用料最省,最后再进一步对车架进行拓扑优化,并对最终的模型进行强度校核。     

中国新疆与中亚地区经贸合作的历程现状与前景

当前新疆与中亚地区经贸合作面临良好发展机遇。本文对新疆与中亚经贸合作的历程进行了回顾,对合作总体现状进行了全面分析,并对与中亚各国的经贸合作进行了比较,继而对合作前景进行了展望。     

Dynamic analysis of a pantograph-catenary system using absolute nodal coordinates

The dynamic interaction between the catenary and the pantographs of high-speed trains is a very important factor that affects the stable electric power supply. In order to design a reliable current collection system, a multibody simulation model can provide an efficient and economical method to analyze the dynamic behavior of the catenary and pantograph. In this article, a dynamic analysis method for a pantograph-catenary system for a high-speed train is presented, employing absolute nodal coordinates and rigid body reference coordinates. The highly flexible catenary is modeled using a nonlinear continuous beam element, which is based on an absolute nodal coordinate formulation. The pantograph is modeled as a rigid multibody system. The analysis results are compared with experimental data obtained from a running high-speed train. In addition, using a derived system equation of motion, the calculation method for the dynamic stress in the catenary conductor is presented. This study may have significance in providing an example that a structural and multibody dynamics model can be unified into one numerical system.     

基于频率法的索力测量系统

为了在工程现场快速方便地检测斜拉桥的拉索索力,依据随机振动法索力检测原理,开发了一种新型的索力测量系统。通过对随机振动法索力检测方法的概述,介绍了该系统的性能、硬件结构和软件模块,并重点阐述了通过数字滤波抑制快速傅里叶分析(FFT)的混频现象、自动扫描确定主振频率和提高索力计算精度的方法和措施。索力测量系统以AT89C55WD单片机(SCM)为平台,集成了电荷放大器、信号分析仪和计算器的相关功能。在工程现场,只需输入少量参数,拉索振动信号采集、信号的快速傅里叶分析和对应的索力计算即可在线自动完成。     

A vehicle type-based approach to model car following behaviors in simulation programs (case study: Car-motorcycle following behavior)

Traffic simulation models often neglect the important role of motorcycles and assume a flow of various combinations of cars. This paper addresses how much different would be the behavior of a car driver while following a motorcyclist compared to cases in which a car follows another car, along with a segment of an urban highway in the non-congested flow. Recognition of such a difference might help to develop existing simulation models and to improve the behavior of car drivers in such a way to lead to lower accidents with motorcycles. To reach the goal, a GHR (Gazis-Herman-Rothery) model for car following is applied and data have been collected by video cameras during 15?min time intervals in three different days. Analysis of 198 car-motorcycle and 374 car-car following observations has indicated that when a car driver follows a motorcycle, keeps a higher headway (about 10?m in the low speed) with a lower acceleration/deceleration in comparison with the situation in which car driver follow another one. It means that the behavior of the follower car driver would be more cautious compared to situations in which a car driver follows another one, especially in space headways <10?m. In addition to main findings of the paper for developing a more realistic simulation program, the paper also addresses that in cases when the required safe space between a car and a motorcycle would be endangered, a warning message could be generated for the car driver (by implementing an in-veh ITS technology) to warn driver about keeping a safe distance.     

面向交通枢纽的车辆三维真实感实时仿真

为分析和解决城市交通拥挤问题并提高城市道路利用率提供可行的途径,提出了一种面向交通枢纽的车辆运行仿真方法,通过场景、道路与车辆的三维动态建模,实现交通枢纽交通状况的实时真实感仿真.首先,提出了基于道路关键点连接网络模型表示交通枢纽的通行道路.其次,基于粒子系统实现车辆的动态运行实时仿真,并采用基于空间剖分的车辆碰撞检测方法对车辆运动控制算法进行了优化.最终,通过对路段的动态观测和反馈机制实现车辆行驶路线的规划和调度.实验结果表明,本文提出的方法可以生动直观地呈现实际路面的交通状况,并且能以较为流畅的帧速率实现交通场景的动态仿真.     

A study on a dynamic model of a vehicle simulator with 6 DOF for the Korean tilting train

This article presents a dynamic model of a railway vehicle for the development of a 6-DOF (degrees of freedom) tilting-train simulator. It will be used to verify the tilting-electronics and tilting-control algorithm that are to be applied to the Korean tilting train. It is composed of 6 electrically driven actuators, a track generation system, a graphic user interface, and a visualization system with a 1600-mm-diameter dome screen. Each system shares the data by means of Ethernet network in real time. In this study, a train model of 9-DOF with a force generation system to tilt the train body has been used. Dynamic analysis for the straight track running and curve negotiation of a railway vehicle can be performed in the model. A verification study for the application of the model to the simulator has been conducted on curving tracks with different radii.     

考虑溶洞空间形态的路基岩溶顶板稳定性分析方法

岩溶路基随岩溶地区交通工程建设的快速发展而越来越普遍,如何评价岩溶路基稳定性成为岩溶区路基设计与施工的关键问题之一。针对目前路基岩溶顶板稳定性分析的不完善性,考虑溶洞形成过程中岩溶顶板所具有的空间形态特征,首先,将路基下伏岩溶顶板简化为固支梁、抛物线拱、圆拱与固支双向板等承载模型,以此进行路基岩溶顶板稳定性分析,并采用结构力学分析理论分别建立不同模型的路基岩溶顶板抗弯最小安全厚度计算方法;其次,通过典型案例的影响因素敏感性分析,揭示岩溶顶板最小安全厚度随溶洞顶板矢高、跨度、岩石抗拉强度与上覆荷载的变化规律,探讨路基岩溶顶板破坏模式的控制性因素及其影响规律,确定岩溶路基稳定性分析的基本原则;然后,基于岩溶地区地质勘察信息提出路基岩溶顶板稳定性分析过程,建立考虑溶洞空间形态特征的路基岩溶顶板稳定性分析方法;最后,通过工程实例计算分析验证所提方法确定的路基岩溶顶板稳定性评价结果的合理性与有效性。研究结果表明：岩溶顶板按何种模式破坏不仅与破坏形式有关,还与溶洞形态及其矢高密切相关,石灰岩抗拉强度同样影响较大,工程设计与稳定性评价时应基于勘测数据分析各种破坏模式,以便使设计或评价结果更接近实际情况。     

Real-time implementation of a traction control algorithm on a scaled roller rig

Traction control is a very important aspect in railway vehicle dynamics. Its optimisation allows improvement of the performance of a locomotive by working close to the limit of adhesion. On the other hand, in case the adhesion limit is surpassed, the wheels are subjected to heavy wear and there is also a big risk that vibrations in the traction occur. Similar considerations can be made in the case of braking. The development and optimisation of a traction/braking control algorithm is a complex activity, because it is usually performed on a real vehicle on the track, where many uncertainties are present due to environmental conditions and vehicle characteristics. This work shows the use of a scaled roller rig to develop and optimise a traction control algorithm on a single wheelset. Measurements performed on the wheelset are used to estimate the optimal adhesion forces by means of a wheel/rail contact algorithm executed in real time. This allows application of the optimal adhesion force.     

Multiphysic modelling of railway vehicles equipped with pneumatic suspensions

This article presents a multidisciplinary approach of railway pneumatic suspension modelling: both multibody and pneumatic aspects are taken into account. The work aims at obtaining a realistic model of the secondary suspension and coupling it with a multibody model of a train. Various components of the pneumatic circuit such as bellows, tanks, pipes and valves are taken into account. The article focuses on the bellow-pipe-tank subsystem for which several modelling approaches are presented and compared. Differences between differential and algebraic models are highlighted, and an application-dependent choice between them is suggested. A complete model of the pneumatic circuit is then obtained and coupled with a multibody model of the train. As a result, the behaviour of a suburban train equipped with a pneumatic secondary suspension is analysed, in particular undesired oscillating motions which affect the comfort. Topological modifications and improvements of the suspension are also investigated and discussed.     

Theoretical method for predicting the weight reduction rate of a box-type car body for rolling stock by material substitution design

In this paper, a theoretical approach is suggested for predicting the structural performances and weight reduction rate of a car body with a box-type section when its material is substituted with a lightweight material for weight saving. For the material substitution design of a car body for rolling stock, bending, axial, and twisting deformations should be considered at constant stiffness and strength conditions. To compare the weight reduction effects on different material applications, some new indices were derived from a structural performance point of view. The derived indices provide good measures to estimate weight reduction by material substitution design and can be effectively applied to the conceptual design of a car body.     

Energy-harvesting potential of automobile suspension

This study is aimed quantify dissipated power in a damper of automobile suspension to predict energy harvesting potential of a passenger car more accurately. Field measurements of power dissipation in a regenerative damper are still rare. The novelty is in using the broad database of real road profiles, a 9 degrees-of-freedom full-car model with real parameters, and a tyre-enveloping contact model. Results were presented as a function of road surface type, velocity and road roughness characterised by International Roughness Index. Results were calculated for 1600 test sections of a total length about 253.5?km. Root mean square of a dissipated power was calculated from 19 to 46?W for all four suspension dampers and velocity 60?km/h and from 24 to 58?W for velocity 90?km/h. Results were compared for a full-car model with a tyre-enveloping road contact, full-car and quarter-car models with a tyre–road point contact. Mean difference among three models in calculated power was a few per cent.