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931.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(8):1204-1226
Real road vehicle tests are time consuming, laborious, and costly, and involve several safety concerns. Road vehicle motion simulators (RVMS) could assist with vehicle testing, and eliminate or reduce the difficulties traditionally associated with conducting vehicle tests. However, such simulators must exhibit a high level of fidelity and accuracy in order to provide realistic and reliable outcomes. In this paper, we review existing RVMS and discuss each of the major RVMS subsystems related to the research and development of vehicle dynamics. The possibility of utilising motion simulators to conduct ride and handling test scenarios is also investigated. 相似文献
932.
《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2012,50(5):789-810
This article presents results of the studies aimed at more accurate stability analysis of railway vehicles in a curved track. More accurate analysis means extended study of the stability as compared with the method used by the authors so far. New measures undertaken by the authors in order to achieve the goal are explained. Besides, differences between results obtained with the earlier and extended approaches are presented and discussed. Results that are expected on the basis of the theory are confronted with practical capabilities to generate them through simulations at the same time. The issues of interest are precise determination of nonlinear critical velocity, determination of linear system critical velocity, determination of unstable periodic and unstable stationary solutions, existence of multiple solutions and correct determination of velocity at which unbounded growth of the solutions (lateral dynamics coordinates) happens during calculations resulting in their stop. 相似文献
933.
列出核燃料运输车2次缓冲装置的纵向动力学微分方程,采用变步长的Runge -Kuta积分法,对其进行了7种工况下的纵向动力学仿真分析。结果表明,在核燃料运输车上采用3级刚度的2次缓冲装置,满足核燃料货包在各种工况下的纵向加速度≤1 5g的要求,而且采用较大的摩擦因数有利于减小核燃料货包的纵向滑动行程 相似文献
934.
C. Christiansen K. Edelvang K. Emeis G. Graf S. Jhmlich J. Kozuch M. Laima T. Leipe A. Lffler L. C. Lund-Hansen A. Miltner K. Pazdro J. Pempkowiak G. Shimmield T. Shimmield J. Smith M. Voss G. Witt 《Journal of Marine Systems》2002,35(3-4)
Processes involved in erosion, transport and deposition of cohesive materials are studied in a transect from shallow (16 m) to deep (47 m) water of the SW Baltic Sea. The wave- and current-induced energy input to the seabed in shallow water is high with strong variability and suspended matter concentrations may double within a few hours. Primary settling fluxes (from sedimentation traps) are less than 10 g m−2 day−1, whereas resuspension fluxes (evaluated from sedimentation flux gradients) are 15–20 times higher and the residence time for suspended matter in the water column is 1–2 days. Settling velocities of aggregates are on average six times higher than for individual particles resulting in an enhanced downward transport of organic matter. Wave-induced resuspension (four to six times per month) takes place with higher shear stresses on the bottom than current-induced resuspension (three to five times per month). The short residence time in the water column and the frequent resuspension events provide a fast operating benthic–pelagic coupling. Due to the high-energy input, the shallow water areas are nondepositional on time scales longer than 1–2 weeks. The sediment is sand partly covered by a thin fluff layer during low-energy periods. The presence of the fluff layer keeps the resuspension threshold very low (<0.023 N m−2) throughout the year. Evaluated from 3-D sediment transport modeling, transport from shallow to deep water is episodic. The net main directions are towards the Arkona Basin (5.5×105 t per year) and the Bornholm Basin (3.7×105 t per year). Energy input to the bottom in deep water is low and takes place much less frequently. Wave-induced resuspension occurs on average once per month. Residence time of particles (based on radioactive isotopes) in the water column is half a year and the sediment accumulation rate is 2.2 mm year−1 in the Arkona Basin. 相似文献
935.
细长海洋结构物涡激振动研究综述 总被引:5,自引:0,他引:5
随着世界范围内深海石油开采的需要,近年来关于海洋结构物涡激振动的研究越来越受到重视.虽然此问题在数值模拟和实验方面都已取得了一定的进展,但是还有许多问题尚待解决.同时,新型海洋结构物的引入给涡激振动的预报方法和抑振手段提出了新的挑战.因此,细长海洋结构物的涡激振动仍将是未来几年里备受关注的研究课题.本文在介绍有关涡激振动基本概念和理论背景的基础上,总结了近年来关于以深水立管为代表的海洋结构物涡激振动的研究与进展,包括对现有涡激振动分析工具的分类与评估;对柱体及海洋结构物涡激振动的实验研究;对深水立管与涡激振动相关的疲劳评估准则的研究;海洋结构物的横向、流向及轴向涡激振动的耦合作用研究;关于海洋结构物涡激振动的抑振措施和设备的理论及实验研究.本文着重介绍了计算流体力学方法在海洋结构物涡激振动研究中的应用和进展.最后,对海洋结构物涡激振动相关的研究热点的现状进行了总结并对今后工作提出了展望. 相似文献
936.
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938.
939.
LUOYue-sheng FANChong-jin TANZhen-fan 《船舶与海洋工程学报》2003,2(1):53-60
By the sketch of structure of MVWG,the working laws of this kind of gyroscope were explained. To the aid of Euler‘‘s Dynamics Equation,a mathematical model of the gyroscope was constructed, and then by the basic working laws of MVWG the model was simplified. Under the conditions of the three axial direction rotations and general rotation, the mathematical model was resolved. And finally by the solutions, the working laws of the gyroscope, the working disparity among all sorts of gyrations and the influences from the gyrations in the axial directions were analysed. 相似文献
940.
电传动机车轮轨动力学性能研究 总被引:3,自引:2,他引:1
采和机车-轨道耦合动力学理论与方法,研究了电传动机车与轨道的动态相互作用问题,以抱轴式驱动系统电力机车为例,建立了机车一轨道查互作用统一的模型,运用VILT领导具软件分析比较了弹性和风性抱轴式电传动机车对轨道的动力作用及牵引电机的振动特性,文章还讨论了牵引中种悬挂方法以动力学性能影响的特征,从而指出其适应范围。 相似文献