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131.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(11):1535-1554
The coupled vehicle/track dynamic model with the flexible wheel set was developed to investigate the effects of polygonal wear on the dynamic stresses of the wheel set axle. In the model, the railway vehicle was modelled by the rigid multibody dynamics. The wheel set was established by the finite element method to analyse the high-frequency oscillation and dynamic stress of wheel set axle induced by the polygonal wear based on the modal stress recovery method. The slab track model was taken into account in which the rail was described by the Timoshenko beam and the three-dimensional solid finite element was employed to establish the concrete slab. Furthermore, the modal superposition method was adopted to calculate the dynamic response of the track. The wheel/rail normal forces and the tangent forces were, respectively, determined by the Hertz nonlinear contact theory and the Shen–Hedrick–Elkins model. Using the coupled vehicle/track dynamic model, the dynamic stresses of wheel set axle with consideration of the ideal polygonal wear and measured polygonal wear were investigated. The results show that the amplitude of wheel/rail normal forces and the dynamic stress of wheel set axle increase as the vehicle speeds rise. Moreover, the impact loads induced by the polygonal wear could excite the resonance of wheel set axle. In the resonance region, the amplitude of the dynamic stress for the wheel set axle would increase considerably comparing with the normal conditions. 相似文献
132.
在传统电机理论的基础上,使用Matlab/Simulink动态仿真软件建立了交流电机及逆变器系统的仿真模型,给出了系统静态、动态过程的仿真数据及实验波形,结果表明,由此建立的系统运行可靠,响应快,可以在仿真研究中使用. 相似文献
133.
The event-related desynchronization/synchronization(ERD/ERS) time courses of lower and upper alpha band rhythms during hand motor imagery are investigated respectively by Fourier Sectral Entropy (FSE) in this paper. By analyzing one group of BCI competition data, it was found that FSE within upper alpha band displays a pronounced increase and decrease over contralateral and ipsilaterai brain areas respectively at the onset of hand motor imagery, which is corresponding to the antagonistic ERD/ERS patterns in previous studies. Different from the upper alpha activity pattern, FSE within lower alpha band displays a consistent increase over both two hemispheres hand representative areas. The preliminary results show that FSE could disclose the different behaviors of the upper and lower alpha band rhythms so that a new idea with the complexity measure is provided to characterize functional dissociation of lower and upper frequency alpha rhythms in relation to hand motor imagery. 相似文献
134.
研究了镀复条件及工艺配方对 N-P-SiC 化学复合镀层中 SiC 均匀共析的影响.结果表明,Nj-P 合金基体中 SiC 微粒子均匀共析的最佳条件是:温度87±1℃,搅拌速度600r/min·K,pH=4.8,SiC 平均粒径 D_p=3.5μm,SiC 的添加量8g/L,析出速度12~14μm/h.本文还测定了镀层的显微硬度及磨损量,并用扫描电镜观察了磨损前后的表面形貌和结构. 相似文献
135.
136.
分析金融危机下中国客车出口情况、国际市场、国际竞争对手的现状及中国客车出口下滑的原因;预测中国客车出口的趋势,并提出应对危机的对策。 相似文献
137.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(10):1563-1584
A virtual test rig is presented using a three-dimensional model of the elasto-kinematic behaviour of a vehicle. A general approach is put forward to determine the three-dimensional position of the body and the main parameters which influence the handling of the vehicle. For the design process, the variable input data are the longitudinal and lateral acceleration and the curve radius, which are defined by the user as a design goal. For the optimisation process, once the vehicle has been built, the variable input data are the travel of the four struts and the steering wheel angle, which is obtained through monitoring the vehicle. The virtual test rig has been applied to a standard vehicle and the validity of the results has been proven. 相似文献
138.
港口装卸设备远程监控系统 总被引:1,自引:0,他引:1
港口装卸设备日益大型化、高速化、自动化.如何能高效快捷地监控港口装卸设备的运行装态,对提高装卸效率、提高码头吞吐量至关重要.文章介绍基于Web的B/S模式的港口设备远程监控系统,具有简单、高效、跨平台等优点;可进行实时监测和控制,实现由上而下的集中管理、分散控制;特别是能够通过互联网络实现远程的监测.对港口企业远程监控系统的建设具有一定的参考作用. 相似文献
139.
对地铁车站低压配电EPS(应急照明电源装置)设计及供电系统交直流操作电源设计方案进行了总结。经过对现有EPS与变电所交直流操作电源合并及分开设置方案进行经济技术性比较,综合考虑可靠性、运营管理便利性、系统综合维护成本后,推荐EPS与变电所操作电源分开设置方案。 相似文献
140.
论述自备客车的运行特点,空调与客车匹配的基本要求,发动机动力要求,空调系统制冷量输出与发动机转速的匹配等问题,确定了安装空调的客车和空调的型号,并对安装后的空调运行进行了调试。 相似文献