武汉市唐家墩立交节点设计形式探讨

武汉市脚家墩立交桥A匝道地铁车站节点,因受到地铁车站及剧边的构造物的限制,桥下不能设置桥墩。采用大跨度的钢横梁与A匝道钢箱梁连接,解决了因空间限制无法布置桥墩的问题。同时也解决了A匝道曲线钢箱梁支座设置及偏心受力的问题。Z78、Z79号双层框架桥墩还兼顺同时支撑主线桥的作川。这种设计方案为多层次立交工程提供了新的设计思路。     

动车组在广深线的运用及检修

概要介绍了广深铁路客运特点,对担当客运任务的X2000新时速摆式动车组、“蓝箭”动车组的运用检修情况作了较为详尽的介绍和技术分析,由此对我国动车组的运用、维护管理方式以及动车组研制等提出了建议。     

FPSO内孤立波载荷特性数值研究

文章将KdV、eKdV和MCC内孤立波理论应用到内孤立波数值模拟水槽入口速度条件计算,讨论内孤立波与浮式生产储卸油装置FPSO强非线性作用问题。结果表明,数值模拟所得FPSO内孤立波水平载荷、垂向载荷及力矩与实验结果相吻合,内孤立波载荷主要由波浪压差力、粘性压差力和摩擦力构成,粘性压差力很小,可以忽略;在水平载荷中,摩擦力较压差力约小一个量级,流体粘性的影响不可忽略;在垂向载荷中,摩擦力比压差力小很多,在分析时可以忽略流体粘性的影响。由于FPSO始终处于上层流体中,对内孤立波的模拟波形和其诱导流场的影响很小。波浪压差力可利用傅汝德-克雷洛夫公式基于动压力进行计算,而水平载荷中的摩擦力则需根据内孤立波诱导速度的切向分量对FPSO吃水湿表面求积分的方法进行计算。     

Automatic generation of the non-holonomic equations of motion for vehicle stability analysis

The mathematical analysis of vehicle stability has been utilised as an important tool in the design, development, and evaluation of vehicle architectures and stability controls. This paper presents a novel method for automatic generation of the linearised equations of motion for mechanical systems that is well suited to vehicle stability analysis. Unlike conventional methods for generating linearised equations of motion in standard linear second order form, the proposed method allows for the analysis of systems with non-holonomic constraints. In the proposed method, the algebraic constraint equations are eliminated after linearisation and reduction to first order. The described method has been successfully applied to an assortment of classic dynamic problems of varying complexity including the classic rolling coin, the planar truck–trailer, and the bicycle, as well as in more recent problems such as a rotor–stator and a benchmark road vehicle with suspension. This method has also been applied in the design and analysis of a novel three-wheeled narrow tilting vehicle with zero roll-stiffness. An application for determining passively stable configurations using the proposed method together with a genetic search algorithm is detailed. The proposed method and software implementation has been shown to be robust and provides invaluable conceptual insight into the stability of vehicles and mechanical systems.     

摆式列车综述(待续)

系统介绍了近30年来国外研制的摆式列车的结构特点.     

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.     

内孤立波环境下半潜式平台受力研究

在2层流体基本假设下,通过实验分别研究不同波浪入射角下,作用在半潜式平台立柱群和沉箱群上的内孤立波载荷特性.实验结果表明:在任意迎流角下,作用在立柱和沉箱各部分的载荷峰值均随波幅增大而线性增大,并且波的传播方向对力的峰值有显著影响.在相同波幅、相同分层比下,当来波方向与平台中纵剖面不平行时,沉箱群水平载荷峰值在迎流角为...     

基于UIO的摆式列车倾摆控制系统执行机构的故障检测

提出了一种利用未知输入观测吕（ＵＩＯ）对摆式列车倾摆控制系统执行机构进行故障检测的方法。该方法是干扰解耦原理的一个应用,通过一个全阶未知输入观测器使残差对未知输入不敏感,而对故障敏感,通过一个简单阈值逻辑来检测故障,通过计算机仿真证明了该方法的有效性。     

摆式电动车组受电弓倾摆系统的模式研究

根据国外的经验，指出采用动力分散的摆式列车可有效减小轴重，降低轮轨横向力和磨耗，是在既有线上提高列车运行速度的有效途径。重点阐述了国外摆式电动车组受电弓系统的倾摆模式，并对其特点进行了系统分析，提出了受电弓倾摆系统设计所需考虑的关键技术。     

水润滑可倾瓦推力轴承设计与性能分析

针对无轴轮缘驱动推进器对高承载、长寿命、低噪音水润滑推力轴承的需求, 设计了一种阶梯橡胶垫支撑的水润滑可倾瓦推力轴承; 应用流-固双向直接耦合分析方法, 建立了轴承性能计算模型, 研究了橡胶垫基体厚度、阶梯厚度、阶梯厚度比、阶梯宽度比和瓦面材料对推力盘轴向位移、最大水膜压力与水膜厚度的影响。研究结果表明: 在载荷不变的情况下, 推力盘轴向位移和橡胶垫最大应力与橡胶垫厚度和橡胶垫阶梯宽度比成正比; 阶梯厚度比由2/2变成3/6时, 最大水膜压力由1.10 MPa提高到1.32 MPa, 平均水膜厚度由9.4μm增大到14.0μm, 增幅分别为20.00%和48.94%, 平均水膜厚度随最大水膜压力的增大而增大; 橡胶垫阶梯厚度比为2/4, 阶梯宽度比为16/20~20/16时, 轴承综合性能较为理想; 增大推力瓦面材料的弹性模量, 有利于提高轴承的润滑性能, 橡胶垫最佳阶梯宽度比随之增大。