A study of locomotive driver's seat vertical suspension system with adjustable damper

This paper shows that laboratory measurements can be used for the identification of structure and parameters of commercial seat vertical suspension system model. A commonly used single-degree-of-freedom suspension model does not suffice. The system model presented is based on Zener's structure and clearly describes the dynamic properties of a vertical seat suspension with an adjustable damper. The model introduced, augmented with seat cushion dynamic model, predicts the seat vertical vibration mitigation properties under field conditions with a reasonable accuracy. Optimisation of the adjustable damper setting is performed using a two-objective function optimisation technique. This enables us to optimise not only the exerted vertical vibration acceleration but also the seat relative vertical displacement (stroke). Optimisation was facilitated for the particular suspended seat without the requirement of further field measurements. In addition, a two-parameter optimisation was performed showing possible further improvement in both objectives at the manufacturer's discretion. This study could be representative of driver's seats equipped with vertical seat suspension system using an air-spring and an adjustable damper.     

Application of observer-based fault detection in vehicle roll control

This paper describes how observer-based techniques for intelligent fault detection were applied to monitoring an active suspension control system in an experimental articulated heavy vehicle. The aim was to define a practical method for detecting faults, taking into account the nonlinearities of the vehicle. The experimental vehicle was divided conceptually into subsystems, namely the passive dynamics of the trailer, the dynamics of the hydraulic actuators, and the expected response of the closed-loop system. A linear dynamic model was designed for each subsystem. A fault detection observer was then designed for each dynamic model. The observer feedback gains were chosen to optimise estimation by the observer residual of specified errors on the output measurements. The observer residuals were then normalised and combined logically to provide a fault diagnosis. The performance of the fault detection scheme is demonstrated in the case of sensor faults and changes in the operation of the active control system.     

上海磁悬浮快速列车工程下部结构设计概况

介绍磁悬浮列车下部结构设计方案以及墩柱类型、基桩类型、桩基持力层的选择等。     

多连杆后悬架托臂强度分析

针对某一轿车行驶6400公里左右时，后悬架托臂出现开裂的现象。本文采用有限元方法，用 Hypermesh软件对后悬架托臂的CAD模型进行有限元网格划分、ABAQUS为求解器，对托臂进行不同工况下的强度校核，根据托臂的应力分布情况来分析断裂的原因，并提出改进方案，为托臂的前期设计提供一种方法。     

重型牵引车空气悬架钢板弹簧支架强度分析与优化

利用有限元分析软件对某重型牵引车空气悬架的钢板弹簧支架进行强度分析。结果表明,在四种典型工况下,钢板弹簧支架的强度均满足要求,并存在一定的材料冗余;在此基础上,对钢板弹簧支架进行拓扑优化,优化后的钢板弹簧支架质量减轻了6.8%,同时仍满足强度要求。     

研究SoLoMo概念与LBS技术融合的汽车4S店售后服务

汽车4S店依赖进销巨额价差获得盈利的时代逐渐消逝,做好销售的同时,借助网络渠道促进汽车4S店售后服务品质提升、规模效益增长和客户群体的稳定是其可持续发展的主要途径。本文通过引入SoLoMo概念与LBS技术完善传统的O2O模式,进而扩大4S店的服务推广以及针对特定登陆位置为客户有效提供差异化服务。从保证售后服务质量为出发点,在O2O平台上建立维修返修处理应用流程,以全新理念、全新方法来提高汽车售后质量,满足客户需求。     

三塔两跨悬索桥猫道拆除施工技术

南京长江第四大桥主桥为主跨1 418m的双塔三跨悬索桥,全桥设置2幅猫道作为主缆施工平台,在主缆主要施工作业完成后需拆除猫道。猫道按照猫道面层、变位钢架、猫道索顺序拆除。猫道面层先采用卷扬机拆除门架处型钢横梁,然后由塔顶向中跨跨中和锚碇方向,边、中跨同步拆除底网和侧网。面层拆除后,用塔吊或汽车吊拆除塔顶两侧和锚碇前方的变位钢架。猫道索拆除按照猫道承载索、扶手索、门架承重索的顺序进行,内侧猫道索下放至主缆内侧钢桥面上拆除,外侧猫道索下放至吊索外桥面检修道上拆除。拆除的猫道索采用收绳架分段收绳、上盘后运输至后场存放。     

大跨自锚式悬索桥吊索张拉与体系转换技术研究

为快速实现大跨自锚式悬索桥体系转换,以(160+406+160)m的双塔三跨自锚式悬索桥——桃花峪黄河大桥为背景,研究以吊索引出量控制为主、索力控制为辅的吊索张拉与体系转换技术。建立实桥有限元模型,计算吊索无应力长度,定义索头引伸出下锚垫板的长度值为引出量;采用引出量控制,从塔根向远离桥塔方向对称张拉吊索(每次8组),跨中几组吊索采取纵向相邻2组同时装千斤顶,在n号吊索张拉的同时,预拉(n+1)号吊索;进行主桥缩尺模型试验,对该方案进行验证及细节优化。研究结果及实际工程表明:采用该体系转换技术方案,主缆与吊索张力、临时墩反力、主梁应力计算值等均满足要求;缩尺模型实测应力、位移与有限元计算值吻合;主梁线形质量好,吊索索力精度高,快速实现了体系转换。     

基于状态空间法的四分之一车辆模型分析

悬架系统是车辆行驶系统中的一个重要组成部分,主要用于吸收和缓冲车辆行驶过程中来自车轮和路面接触产生的振动,车辆行驶的平顺性主要靠悬架系统来保证。本文采用两自由度四分之一车辆模型对悬架系统动力学模型进行建模,结合状态空间分析法分析不同悬架等效刚度和阻尼、不同轮胎等效刚度、不同车辆载重等情况下对车辆行驶平顺性的影响,为悬架的优化设计提供参考。     

汽车轮毂轴承失效模式分析及性能提升

轮毂轴承是汽车非常重要的安全部件,本论文列举某车型路试过程中轮毂轴承单元失效的问题进行分析,针对其失效的原因采取相应轴承性能提升的措施。