Simulation analysis on the coupler behaviour and its influence on the braking safety of locomotive

In order to simulate the runtime behaviour of coupler and buffer systems accurately, the dynamic model was improved by adopting the polygonal contact model. And the reliability of the friction phenomenon in flat-pin coupler’s tail and the connecting constraint between coupler heads were verified. Then the detailed model which fully considered the dynamic characteristics of middle locomotive and its adjacent wagons was incorporated into the simplified longitudinal dynamic model of combined heavy-haul train. The dynamic response of coupler and its influence on the running safety of locomotive under flat straight line emergency braking condition and long steep grade cycle braking condition were simulated respectively. According to the simulation results, the following suggestions were proposed: flat-pin coupler is more suitable for heavy-haul locomotive, but the inspection work on the friction surface of coupler tail needs to be strengthened; and the vertical anti-off stopping device should be added to avoid the occurrence of decoupling accidents.     

无单元法在孔洞应力集中问题中的应用

基于滑动最小二乘近似的无单元法摆脱了有限元法节点和单元之间彼此联系的约束，能够比较自由地根据实际几何实体情况布置节点、积分子区域，并能够根据可能的位移形式采取合适的基函数。本文对无单元法的基本理论进行了简要阐述，并以孔洞应力集中问题作为数值算例来说明无单元法在求解边值总是上的灵活性。     

Effect of vehicle vibration environment of high-speed train on dynamic performance of axle box bearing

In this study, we developed a comprehensive three-dimensional vehicle–track coupled dynamics model considering the traction drive system and axle box bearing. In this model, dynamic interactions between the axle box bearing and other components, such as the wheelset and bogie frame, are considered based on a detailed analysis of the structural properties and working mechanism of the axle box bearing. A few complicated dynamic excitations, such as the time-varying mesh stiffness of gears, time-varying stiffness of bearing, bearing gaps and track irregularities, are considered. Then, the dynamic responses of the vehicle–track system are demonstrated via numerical simulations based on the established dynamics model. The results indicate that the traction drive system and track irregularities can significantly influence the dynamic interactions of the axle box bearing. The necessity of considering the excitation caused by gear meshing and track irregularities when assessing the dynamic performance of the axle box bearing is demonstrated.     

基于潜在冲突量的交叉口安全评价方法研究

提出了潜在冲突量的概念，并对其进行了分类。通过车速、交通量、车道宽度等易获取的交通参数来推算交叉口潜在冲突量。引入混合交通当量，将潜在冲突量与混合交通当量比值作为交叉口安全评价的指标，并选取灰色聚类的方法对交叉口进行安全程度的评价。对桂林市的9个交叉口进行了安全程度的评价，评价结果与实际状况相吻合。     

内燃机车柴油机动力系统关键零部件

1柴油机活塞柴油机活塞、活塞环和气缸套是柴油机的心脏。活塞从制造方法而青，有锻造与铸造之分；从材料与种类而言，主要有铝活塞、钢活塞、整体球铁活塞和钢顶铁裙、钢顶铝裙组合式活塞等。衡量活塞的制造水平，一般有几个方面：     

基于SPH方法的电驱动减速器飞溅润滑仿真

电驱动减速器是纯电动汽车传动系统的核心部件,对其进行合理有效的润滑尤为重要。应用SPH(光滑粒子流体动力学)方法对电驱动减速器飞溅润滑仿真分析,基于SPH方法的PreonLab软件仿真分析两种不同转速工况后,处理结果显示,仿真结果与试验结果在搅油形态上具有较好的一致性,验证了该方法进行减速器飞溅润滑仿真的可行性和有效性。     

CompactPCI热插拔系统设计与应用

热插拔是CPCI系统最重要和最具优势的特点。目前,业界尚没有一种能够同时支持基本热插拔、完全热插拔和高可靠性热插拔的实现方案。提供了一种CPCI热插拔系统,分别从系统架构、软件架构、各组成部分的数据流交互、热插拔驱动以及守护进程的工作流程5个方面阐述了整个系统的硬件和软件实现。该热插拔系统符合CPCI热插拔规范,能够同时支持基本热插拔、完全热插拔和高可靠性热插拔。     

光纤陀螺罗经辅助ADCP导航方法研究

研究了利用光纤陀螺罗经辅助声学多普勒流剖面仪(acoustic Doppler current profile-ADCP)进行导航定位的方法,分析比较了ADCP独立进行航位推算和光纤陀螺罗经辅助ADCP进行组合导航的精度,研究结果表明,光纤陀螺罗经辅助ADCP进行组合导航的精度至少提高1倍以上.其定位精度可以达到130m/h.     

新型自动插拔低架滑触线轮胎吊油改电系统

介绍轮胎吊低架油改电技术的发展以及各种自动插拔方案,并进行系统比较,阐述连云港新东方集装箱码头选用的新型自动插拔低架滑触线轮胎吊油改电方案的设计内容、实施情况和使用效果。     

刚性接触网动态检测技术

分析接触网检测技术在国内外的发展状况,介绍刚性接触网检测车系统的组成和功能、刚性检测项目和原理及目前刚性检测技术存在的问题,阐明刚性接触网动态检测技术与柔性网检测的不同点及刚性接触网专用检测技术的必要性。