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排序方式: 共有593条查询结果,搜索用时 31 毫秒
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Ulrich Spangenberg Robert Desmond Fröhling Pieter Schalk Els 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2019,57(1):44-63
There are many reasons to optimise the wheel–rail interface through redesign or maintenance. Minimising wear and rolling contact fatigue (RCF) initiation on wheels and/or rails is often at the forefront of such considerations. This paper covers the design of a conformal wheel profile and its long-term wear and RCF performance to optimise the wheel–rail interface and subsequently reduce the occurrence of surface-initiated RCF on South Africa’s iron ore export line. A comparative study is performed using multibody dynamics simulation together with numerical wheel wear and RCF predictions. The advantages of a conformal wheel profile design are illustrated by evaluating the worn shape and resulting contact conditions of the conformal design. The conformal design has a steadier equivalent conicity progression and a smaller conicity range compared with the current wheel profile design over the wheel’s wear life. The combination of a conformal wheel profile design with 2?mm hollow wear and inadequate adherence to grinding tolerances often result in two-point contact, thereby increasing the probability of RCF initiation. The conformal wheel profile design proved to have wear and potential RCF benefits compared with the current wheel profile design. However, implementation of such a conformal wheel profile must be accompanied by improved rail grinding practices to ensure rail profile compliance. 相似文献
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《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(7):869-889
This paper presents two extensions of Kalker's algorithm Fastsim of the simplified theory of rolling contact. The first extension is for solving tangential contact problems with the coefficient of friction depending on slip velocity. Two friction laws have been considered: with and without recuperation of the static friction. According to the tribological hypothesis for metallic bodies shear failure, the friction law without recuperation of static friction is more suitable for wheel and rail than the other one. Sample results present local quantities inside the contact area (division to slip and adhesion, traction) as well as global ones (creep forces as functions of creepages and rolling velocity). For the coefficient of friction diminishing with slip, the creep forces decay after reaching the maximum and they depend on the rolling velocity. The second extension is for solving tangential contact problems with friction anisotropy characterised by a convex set of the permissible tangential tractions. The effect of the anisotropy has been shown on examples of rolling without spin and in the presence of pure spin for the elliptical set. The friction anisotropy influences tangential tractions and creep forces. Sample results present local and global quantities. Both extensions have been described with the same language of formulation and they may be merged into one, joint algorithm. 相似文献
555.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(8):1299-1320
Flexible-wheel (FW) suspension concept has been regarded to be one of the novel technologies for future planetary surface vehicles (PSVs). This study develops generalised models for fundamental stiffness and damping properties and power consumption characteristics of the FW suspension with and without considering wheel-hub dimensions. Compliance rolling resistance (CRR) coefficient is also defined and derived for the FW suspension. Based on the generalised models and two dimensionless measures, suspension properties are analysed for two FW suspension configurations. The sensitivity analysis is performed to investigate the effects of the design parameters and operating conditions on the CRR and power consumption characteristic of the FW suspension. The modelling generalisation permits analyses of fundamental properties and power consumption characteristics of different FW suspension designs in a uniform and very convenient manner, which would serve as a theoretical foundation for the design of FW suspensions for future PSVs. 相似文献
556.
曲线上车辆脱轨和钢轨磨耗的原因 总被引:3,自引:0,他引:3
通过对曲线区段列车安全通过和降低轮对轮缘与钢轨磨耗问题的研究,提出将外轨超高降低和把钢轨润滑从外轨改为内轨顶面两点措施,从而减轻了轮缘与轨头的侧向磨耗,提高了车辆运行的安全性。 相似文献
557.
我国城轨交通若干技术发展趋向探讨 总被引:1,自引:1,他引:0
对我国城市轨道交通建设发展过程中的车辆、列车控制、自动售检票、屏蔽门、轻轨交通发展、列车运行最高速度、多种形式城轨交通使用条件等若干技术发展趋向进行探计,企盼我国城轨交通建设更为科学、合理。 相似文献
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为满足单舵或联动双舵结构设计舵减摇控制时的单输入要求,使控制器对海浪的扰动具有鲁棒性,针对一类受到持续扰动的系统,提出了保吸引子扰动抑制控制概念.结合反步设计方法、Barbalat引理和Lyapunov分析方法,通过求解代数Riccati方程,得到了该系统的标量自适应鲁棒控制器;将受控系统的状态抑制在一个有界的吸引子内,利用线性矩阵不等式给出吸引子最小化的判据,优化了扰动抑制控制.以渔政船1500HP在小风浪中的弱混沌横摇现象为例,用本文设计的扰动抑制控制器作为操舵力矩进行混沌横摇控制,通过数值仿真验证了保吸引子扰动抑制控制的效果.结果表明:保吸引子控制器使横摇系统的状态快速收敛,并将其抑制在预设的吸引子内,优化吸引子控制器能使吸引子进一步压缩. 相似文献