In present study, the aerodynamic fatigue behaviour of train equipment cabin was investigated. Pressure sensors were arranged at train passing side. Eight‐grade load spectrum was constructed by means of rain‐flow counting, and fatigue damage was calculated with Miner's rule and Carten‐Dolan rule, both for the matrix metals and welds. For welds, defect detection was considered via visual inspection with nondestructive test (VI‐NDT), pure nondestructive test (P‐NDT), and without nondestructive test (W‐NDT). The result confirms that welds play an unfavourable role rather than matrix metals. Weld damage in W‐NDT exceeds its limit (1.0) to designed mileage. Then, damage influence was studied under tunnel passing, train passing, and running direction. Running direction as the head car contributes 82% to approximately 86% and 70% to approximately 77% of the total damage for matrix metal and welds, respectively. Train passing gives more damage to matrix metals than welds. Tunnel passing contributes 25% to approximately 26% for both matrix metals and welds.
This paper proposes a novel guidance magnet with 7 magnet poles for application in high speed maglev train. Its configuration and working principle are introduced in detail. Mathematical models of the guidance force and moment are established accurately by equivalent magnetic circuit method (EMCM), from which the relationships of guidance force -control current -guidance gap and moment -current changeangular deflection are derived. Finite element method (FEM) is also applied to analyze the performances and characteristics of the novel guidance magnet. The analysis results are in good agreement with those calculated by EMCM, which is helpful in designing, optimizing and controlling the guidance system. The comparisons are carried out between the novel and conventional guidance magnets. The contrast results indicate that the proposed novel guidance magnet possesses better performances compared to the conventional structure, especially the superior guidance capability and lower power loss. Finally, the relationship of guidance forcecontrol current under the nominal guidance gap is validated by a test bench for magnet performance.
High‐speed Maglev is a cutting‐edge technology brought back into the focus of research by plans of the Chinese government for the development of a new 600 km/h Maglev train. A Chinese‐German cooperation with industrial and academic partners has been established to pursue this ambitious goal and bring together experts from multiple disciplines. This contribution presents the joint work and achievements of CRRC Qingdao Sifang, thyssenkrupp Transrapid, CDFEB, and the ITM of the University of Stuttgart, regarding research and development in the field of high‐speed Maglev systems. Furthermore, an overview is given of the historical development of the Transrapid in Germany, the associated development of dynamical simulation models, and recent developments regarding high‐speed Maglev trains in China.
PurposeThe nose length is the key design parameter affecting the aerodynamic performance of high-speed maglev train, and the horizontal profile has a significant impact on the aerodynamic lift of the leading and trailing cars Hence, the study analyzes aerodynamic parameters with multi-objective optimization design.Design/methodology/approachThe nose of normal temperature and normal conduction high-speed maglev train is divided into streamlined part and equipment cabin according to its geometric characteristics. Then the modified vehicle modeling function (VMF) parameterization method and surface discretization method are adopted for the parametric design of the nose. For the 12 key design parameters extracted, combined with computational fluid dynamics (CFD), support vector machine (SVR) model and multi-objective particle swarm optimization (MPSO) algorithm, the multi-objective aerodynamic optimization design of high-speed maglev train nose and the sensitivity analysis of design parameters are carried out with aerodynamic drag coefficient of the whole vehicle and the aerodynamic lift coefficient of the trailing car as the optimization objectives and the aerodynamic lift coefficient of the leading car as the constraint. The engineering improvement and wind tunnel test verification of the optimized shape are done.FindingsResults show that the parametric design method can use less design parameters to describe the nose shape of high-speed maglev train. The prediction accuracy of the SVR model with the reduced amount of calculation and improved optimization efficiency meets the design requirements.Originality/valueCompared with the original shape, the aerodynamic drag coefficient of the whole vehicle is reduced by 19.2%, and the aerodynamic lift coefficients of the leading and trailing cars are reduced by 24.8 and 51.3%, respectively, after adopting the optimized shape modified according to engineering design requirements.
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