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1

The effect of different marshalling forms on the aerodynamic performance of the freight train under crosswind

Xie Zihao, Wu Zhenfeng, Zhu Longhui, Ding Wangcai

Archives of Transport

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2021

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Vol. 59, iss. 3

57--71

EN

Different types and quantities of freight cars will affect the marshalling forms of freight trains. In order to investigate the influence of the marshalling forms on the aerodynamic performance of freight trains under crosswind, three types of freight cars such as box cars, gondola cars and tank cars, were selected to marshal with locomotives. This paper used Detached Eddy Simulation method (DES) based on the SST k-ω turbulent model to simulate the aerodynamic performance of the freight train under crosswind. The wind speed, wind angle and train running speed were set as 25m/s, 45° and 100km/h respectively. The influence of different marshalling forms on the aerodynamic performance of the freight train such as aerodynamic drag and lateral force were calculated and compared. The results showed that the marshalling forms have significant effect on the aerodynamic drag and the maximum difference of the aerodynamic drag can reach 20.5%. Furthermore, the variations of the lateral force of the whole train and the locomotive are not apparent. The maximum difference is only 4.3% and 4.1% respectively. However, the changes of marshalling forms have obvious influence on the lateral force of each carriage. The maximum difference of the lateral force of the box car, gondola car and tank car is 17%, 20.1% and 24.1% respectively. The essential reason why the marshalling forms has a significant impact on the aerodynamic performance of the freight train is that there are obvious differences in the volume and shape structure of each railway carriage. The large volume of box cars and the cavity structure of gondola cars make their position a key factor affecting the aerodynamic performance of freight trains. Among the six different marshalling forms selected in this paper, the best marshalling form is: locomotive--gondola car--box car--tank car. Both the aerodynamic drag of the train and the lateral force of the boxcar are the smallest by taking this marshalling form.

2

Optimum positioning of shear walls for minimizing the effects of lateral forces in multistorey-buildings

Titiksh A., Bhatt G.

Archives of Civil Engineering

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2017

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Vol. 63, nr 1

151--162

EN

Shear walls are the most commonly used lateral load resisting systems in high rises. They have high plane stiffness and strength which can be used to simultaneously resist large horizontal loads while also supporting gravity loads. Hence it is necessary to determine effective and ideal locations of shear walls. Shear wall arrangement must be absolutely accurate, if not, it may cause negative effects instead. In this project, a study has been carried out to determine the effects of additions of shear walls and also the optimum structural configuration of multistory buildings by changing the shear wall locations radically. Four different cases of shear wall positions for G+10 storey buildings have been analyzed by computer application software ETABS. The framed structure was subjected to lateral and gravity loading in accordance with the Indian Standards provision and the results were analyzed to determine the optimum positioning of the shear walls.

PL

Ściany oporowe są prawdopodobnie jednym z najczęściej stosowanych systemów bocznego obciążenia w średnich i wysokich budynkach. Charakteryzują się one wysoką sztywnością płaszczyzny oraz wytrzymałością. Mogą one wytrzymać duże poziome obciążenia oraz obciążenie grawitacyjne. Zastosowanie ścian oporowych staje się obecnie nieuniknione w przypadku konstrukcji wielokondygnacyjnych. Stąd też bardzo istotne jest określenie skutecznego, efektywnego i idealnego położenia ściany oporowej w budynkach. Układ ściany oporowej musi być bardzo dokładny, bo jeśli nie, może powodować negatywne skutki. Prawidłowo zaprojektowane budynki ze ścianami oporowymi dały bardzo dobre wyniki podczas ostatnich trzęsień ziemi. Ściany oporowe gwarantują dużą wytrzymałość i sztywność budynków, zgodnie z kierunkiem ich orientacji, co znacznie zmniejsza boczne kołysanie budynku, a tym samym ogranicza możliwość uszkodzenia konstrukcji i jej zawartości. Ściany oporowe w regionach o wysokiej aktywności sejsmicznej wymagają specjalnych detali. Przepisy dotyczące detali monolitycznych konstrukcji żelbetowych i konstrukcji ze ścian oporowych zostały opisane w IS 13920 (1993). Po trzęsieniu ziemi w Bhuj, które miało miejsce w 2001 roku, kodeks ten stał się obowiązkowy dla wszystkich konstrukcji w strefach III, IV i V.

3

Research of lateral force of pipe conveyor belt’s vertical transport section

Wang S., Guo Y.-C., Li D. Y., Hu K.

Archives of Transport

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2016

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Vol. 37, iss. 1

67--75

EN

In order to release the lateral force of pipe conveyor belt in vertical transportation, the thesis had a study of the lateral force of the conveyor belt. By making use of Janssen Principles and fractal theory, based on reasonable simplification, the author established a mathematical model of the lateral force in vertical transportation, and with the research foundation of the pipe belt conveyor for underground transportation, through solution analysis, the author found out that the change of material diameter would lead to nonlinear variation of the lateral force of the conveyor belt. Under the circumstances of different material diameter, discrete element method was adopted to simulate the lateral force of the conveyor belt, thus working out the distribution curve chart of the lateral force. To verify the reliability of the theory, the author built an experimental platform for pipe conveyor belt in vertical transportation, and experimented with five groups of materials in different diameter, working out the strain of lateral force of the characteristic conveyor belt; by comparing the theoretical result, the simulation result and the experimental result, it showed that the solution to relieving lateral force through optimization selection of material diameter put forward in this thesis was reasonable and effective. It provides theoretical reference for the design of pipe belt conveyor.