基于仿真软件Simulink/SimMechanics的铰接式列车动力学建模

将仿真软件Matlab中的Simulink和SimMechanics相结合,建立了两节车辆编组的铰接式列车的时域曲线。通过动力学仿真模型,并根据此模型的仿真结果验证了该建模方法的正确性,说明SimMechanics能够补足Simulink的建模功能,并可以作为一种新的建模工具引入到轨道车辆的动力学仿真中。     

铰接式轻轨车辆称重调簧工艺研究

针对铰接式轻轨车辆的结构特点,通过对其称重调簧前期工艺的研究提出了铰接车辆称重设备的适应性改造方案,并结合一般城轨车辆的称重调簧经验,研究分析铰接式车辆的实际调簧过程,提出了铰接车辆称重调簧的工艺过程及具体的调簧方法。经实验验证,该工艺方法操作便利、简捷易行,极大地提高了铰接车辆的称重调簧效率。     

Dynamic model and validation of an articulated steering wheel loader on slopes and over obstacles

This paper devotes both analytical and experimental efforts in developing a comprehensive dynamic model for an articulated steering wheel loader. The general motion of a wheel loader without suspension is described by seven degrees of freedom (DOF) (three for translation and four for rotation) in this model, which can be used to study the problem of wheel loader dynamics on slopes and over obstacles. A scale wheel loader was designed and manufactured to validate the dynamic model in three conditions (turning on level ground, turning on slopes, and passing over obstacles). The test results reasonably agree with the simulation results. The developed dynamic model was found to be useful and could serve as an important tool for analysing the stability of wheel loaders.     

城轨列车铰接式转向架方案及其动力学性能研究

介绍了城轨列车铰接式转向架基本结构组成,建立了5联单元车组的动力学模型,利用SIMPACK多体动力学仿真软件对单元车组进行了运行安全性、稳定性、平稳性和曲线通过性能分析。仿真分析结果表明,城轨列车铰接式转向架具有良好的动力学性能,能满足城市轨道交通车辆的运行要求。     

基于概率的机车过分相过电压仿真实测及其机理研究

分析了不同变压器接线方式下所产生的两供电臂电压相位差对关节式过分相感应电压大小的影响;并通过仿真模拟机车进入和离开中性段时所产生的操作过电压;中性段上可能由于操作过电压激发铁磁谐振,铁磁谐振情况下右侧供电臂通过受电弓接入中性段所产生的操作过电压是造成放电间隙击穿的主要原因;用实测和仿真结果证实了分析结果。指出通过装设谐振抑制装置可以将操作过电压限制在可接受范围内,避免引起变电所跳闸。     

Structural analysis of 3D high-speed train–bridge interactions for simple train load models

Three-dimensional models are developed for analysing the dynamic interaction that occurs between high-speed trains and bridges. The reliability and accuracy of developed models are verified by comparing the results from analysing field tests on high-speed trains. A number of train load models are proposed and their performances are compared in order to identify possible models that would reduce the computational and modelling efforts while maintaining suitable accuracy. The results show that at least 16 cars out of a 20-car train should be modelled to achieve results that are comparable to those obtained using the highly detailed 20-car model. Regarding the simplified train load model, more accurate results are obtained employing the 3D moving vehicle model for power cars, the heaviest cars of a high-speed trainset, and a moving force model for other cars, power passenger cars, and passenger cars, compared with highly detailed 20-car model.     

铰接式土压平衡盾构辅助测控系统研制技术

在消化吸收国外盾构测控技术的基础上,结合国家863计划“砂砾地层盾构切削和测控系统研究”课题实践,总结了研究开发盾构辅助测控系统的设计方案、优化国外盾构测控系统功能的技术路线以及实施过程中的关键技术,详细介绍了测控系统的软硬件结构和采用的接口方案。     

Application of path analysis methodology to transit system maintenance performance

This paper develops a conceptual framework for bus maintenance based on path analysis and applies it to forty-eight bus transit systems. The application determines the total, direct, and indirect effects of the variables identified as having significant causal links with maintenance cost per mile. These variables are identified using the stepwise regression method. The findings are that the wage rate and fleet size increase maintenance cost directly and indirectly. In terms of the standardized regression coefficients, fleet size has been found to be the most important factor affecting maintenance cost per mile, followed by the proportion of articulated buses, the wage rate and local subsidy in that order. The proportion of articulated buses has been found to reduce maintenance cost per mile directly and to increase it indirectly. The indirect path coefficient of the proportion of articulated buses is 0.1794 whereas the direct path coefficient is –0.351. Similarly local subsidy as a proportion of revenue increases maintenance cost per mile directly and reduces it indirectly. The corresponding path coefficients for the direct and indirect effects of local subsidy are 0.2553 and –0.1073. In addition population density and the peak-base ratio are positively and significantly associated with miles between roadcalls. The implications of these findings are briefly examined in this paper. Because the path analysis methodology allows the direct and indirect effects of a causal variable to be determined, it is recommended for policy analysis.     

铰接式自卸车液压转向系统的特性分析

介绍一种用于铰接式自卸车的转向流量阀,通过对其结构的分析,得出了其流量放大的原理,从而解决了铰接式自卸车使用普通的液压转向装置,无法为转向执行元件提供足够流量的难题,保证了铰接式自卸车正常安全实现转向.     

超长悬臂钢-砼组合行车道梁的理论分析与试验研究

长沙市洪山大桥是一座竖琴式无背索斜塔斜拉桥,主跨跨径206 m,主梁为脊骨梁布置形式,两侧挑梁采用13 m超长悬臂钢-砼组合梁结构,纵向间距4 m.为了准确把握钢挑梁的受力特性,提出了采用修正的铰接梁法计算钢挑梁的荷载横向分布系数,推导了详细的计算公式,并进行了模型试验研究予以验证,试验结果与理论分析结果吻合良好;采用压重320 kN的方法解决负弯矩区域砼板的开裂问题;综合比较各种规范关于砼收缩徐变的规定;分析了砼板的裂缝宽度;为大桥设计和类似工程提供重要的参考和指导.