一种客车变速器控制拉线防冻装置设计

根据调查发现,某型客车在严寒环境下使用时,其手动变速器换挡控制拉线存在卡滞或被冻住的缺陷.本文设计一种变速器控制拉线防冻装置,能有效改善严寒环境下变速器换挡操作的平顺性和客车行驶的安全性.     

电缆耦合的传输线分析预测技术

针对工程中的电缆耦合问题,着重探讨了电缆耦合预测的计算方法。运用多导体传输线的理论建立电缆耦合的等效电路模型,分析了有损传输线上的电压电流分分布。在此基础上,借助软件工具进行仿真计算,分析了电缆耦合的影响因素以及耦合干扰传输特性,从而实现对电缆耦合的综合预测分析。     

Wave scattering by undulating bed topography in a two-layer ocean

The problem of wave scattering by undulating bed topography in a two-layer ocean is investigated on the basis of linear theory. In a two-layer fluid with the upper layer having a free surface, there exist two modes of waves propagating at both the free surface of the upper layer and the interface between the two layers. Due to a wave train of a particular mode incident on an obstacle which is bottom-standing on the lower layer, reflected and transmitted waves of both modes are created by the obstacle. For small undulations on the bottom of the lower layer, a perturbation method is employed to obtain first-order reflection and transmission coefficients of both modes for incident wave trains of again both modes in terms of integrals involving the bed-shape function. For sinusoidal undulations, numerical results are presented graphically to illustrate the energy transfer between the waves of different modes by the undulating bed. U. BASU was born in 1949. She is a professor in the Department Applied Mathematics, Calcutta University, India. Her current research interests include water wave problems, continuum mechanics, etc.     

汽车变速器齿轮的三维建模及参数化设计

在CATIA环境下,以汽车变速器齿轮为例,介绍斜齿轮三维参数化建模的方法,并对变速器各档齿轮的设计予以说明。     

大型活动中突发事件对交通流的时空影响

为了研究大型活动消散过程中交通流分布状况,分析了大型活动中突发事件对交通流分布的时空影响特征,总结了突发事件下常用的交通管制和疏导措施,将静态多路径交通分配方法与元胞传输模型(CTM)相结合,设计出了适合突发事件下的准动态交通分配方法.对一个小规模路网进行仿真,计算了突发事件下各交叉口节点的拥堵时刻,研究了路网拥堵的形成及消散的时空变化规律,并对两组不同管控方案下交通流疏散效率进行了对比.对比结果表明:不同控制方案下的路网在仿真时段内平均车辆延误分别为197、232 S·pcu-1,由该指标可以判断方案一优于方案二,因此,基于CTM的准动态交通分配方法可定量评价突发事件下交通组织方案的效果.     

两万吨列车纵向动力学性能预测

开发了基于空气制动系统仿真的列车纵向动力学仿真程序．通过单车撞击试验获得缓冲器本构关系,通过仿真获得1＋2＋1编组两万吨列车制动特性．计算了两万吨列车车钩力分布特性,在受力特点上看,1＋2＋1编组列车在制动时可以看作中间分界的两段列车,每段列车前部受压,后部受拉．最大车钩力发生在列车的约1／8处,最大拉钩力发生在列车的约7／8处．后部机车滞后于前部机车制动,将使受压车辆数目增多,最大压钩力增加、发生位置后移,最大拉钩力变化不大．车钩间隙越大,车钩力越大．初速度越高,车钩力越小．     

视频传输系统在公路隧道视频监控中的选择和应用

对不同视频传输系统方案进行技术分析比较,介绍点对点式的传输方案在台金高速公路苍岭隧道中的应用情况,探讨视频传输方案在高速公路隧道视频监控系统中的选择和应用。     

Analysis of planetary gear hybrid powertrain system part 2: Output split system

In recent studies, various types of multi-mode electric variable transmissions for hybrid electric vehicles have been proposed. A multi-mode electric variable transmission consists of two or more different types of a planetary gear hybrid powertrain system (PGHP), which can change power flow type using clutches to improve transmission efficiency. Input split systems are generally used for the single-mode powertrain because of their overall superiority, but other power split systems such as output split and compound split systems can be used in the dual-mode powertrain. In this study, we analyze the power transmission characteristics of output split systems, and evaluate their fuel economies in the FTP72 cycle, acceleration performance, and constant vehicle speeds. These results enable the selection of appropriate systems for a dual-mode powertrain.     

黄墩大桥索塔锚固区传力途径和受力分析

为验证索塔锚固区设计的合理性,了解索力在锚固区的传递途径以及主要板件的受力特点,通过全真的实体有限元模型对黄墩大桥索塔锚固区进行了计算分析。计算结果显示:锚固区的索力传递途径明确,能适应斜拉桥的受力特点;钢横梁两端受压,中间受拉,除锚固板与腹板的连接焊缝附近有应力集中现象外,其余板件的应力值均小于材料屈服强度;混凝土塔壁主拉应力较小,配置普通钢筋即可,不必设置环向预应力筋;位于牛腿焊缝附近的剪力钉受力较大,通过加密调整后满足受力要求。上述结果表明黄墩大桥索塔锚固区设计合理、实用,能满足结构受力需要。     

非对称齿形加工的计算机仿真

根据Willis定理,设计出计算机仿真程序．由非对称齿轮滚刀齿形自动生成非对称齿轮齿形,并用AUTOCAD绘制齿形图．根据该齿形图修正滚刀设计,直到齿形满足设计要求为止．