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1

Experimental investigation of tire performance on slush

Ružinskas Andrius, Giessler Martin, Gauterin Frank, Wiese Klaus, Bogdevičius Marijonas

Eksploatacja i Niezawodność

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2021

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Vol. 23, no. 1

103--109

EN

An investigation of tires behaviour on winter roads was always a high importance in the context of road safety. This paper presents the experimental investigation of tire performance on slush that is identified as two mixtures: a mixture of snow and water, and a mixture of crushed ice and water. The measurements of longitudinal and lateral performance including tire traction, braking and cornering were performed. Tire traction tests were performed for both mixtures with different amount of material. A decreasing in the tire friction was observed when amount of the mixture of snow and water was increased twice. For the mixture of crushed ice and water, an opposite trend was observed. The standard deviation values for the peak force coefficient showed a good reproducibility and reliability of performed tire tests.

2

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.

3

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.

4

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.

5

Investigation of dynamic properties of vehicle in various friction condition simulated with use of skidcar system

Žuraulis V., Kemzūraitė K., Więckowski D.

Archiwum Motoryzacji

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2014

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Vol. 63, nr 1

89--99, 195--205

EN

In this paper, the friction characteristics of a vehicle equipped with skidcar system are analyzed. Skidcar system with attached additional wheels helps to regulate the adhesion with the road surface. Easy slipping vehicle is a useful device for driving skills improvement, carrying out various vehicle dynamics and control research activities. Important reason of skidcar systems is an ability to set low friction values in dry and good contact road conditions. Regulation of friction characteristics extends the limits of the system operation. In this case, the identification of friction characteristics is important. Vertical load of wheels and critical horizontal forces are measured in each operating mode by changing skidcar system height. Furthermore, IS04138 driving manoeuvre is performed to measure the vehicle accelerations, oscillations and slip parameters for friction evaluation in dynamic state. The performed analysis could be useful for drivers training and for further vehicle stability and control researches upon using skidcar system.

6

Side Forces and Stabilization Moment Reasearch for Winter and Summer Tires

Waluś K. J.

Machine Dynamics Research

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2012

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Vol. 36, No. 3

95-102

EN

Vehicle subjected to specified external excitations is subjected to three-axial loads. Vehicle movements generated directional forces are transmitted through the coupling tire with the road. The value of these forces depends on the angle of the lateral drift, vehicle parameters and surface type. Lateral drift forces and moment stabilizing direct interferences on the front tire and indirectly by steering to the driver. An excessive increase in these forces makes it difficult to control the vehicle, and exceeded the limit of grip may result in loss of vehicle control. The paper presents results of experimental determination of the lateral drift forces and moment stabilizing the running on the machine using five-component hub.

7

An influence of some process parameters on lateral forces in forging dies

Kocańda A., Czyżewski P.

Computer Methods in Materials Science

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2007

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Vol. 7, No. 2

208-211

EN

The lateral forces are relatively high in production of nonsymmetrical or extended forgings what results in an offset of the upper and lower dies. Two industrial forging processes for the bracket lever and the valve lever were analyzed. MSC/SuperForge software based on finite yolume method has been used in numerical modeling of the processes. Combined thermo-mechanical numerical analysis took into account all stages of the forging processes. Changes in the inclination of parting line of dies and geometry of preforms resulted in considerable changes in distribution of force components. The results of calculations have been very helpful in finding the process parameters for which the lateral forces were relatively Iow.

PL

Przy kuciu odkuwek wydłużonych i niesymetrycznych występują w wykrojach matryc znaczne siły poprzeczne, które mogą doprowadzić do wzajemnych przesunięć matryc dolnych i górnych, a tym samym - wad geometrycznych odkuwek. W referacie przedstawiono analizę dwóch przemysłowych procesów kucia dźwigni ze stali średniowęglowych. Przeprowadzono modelowanie komputerowe tych procesów metodą objętości skończonych (program MSC SuperForge). Złożona analiza termo-mechaniczna uwzględniła wszystkie etapy procesów. Zmiany w położeniu powierzchni podziału matryc i zmiany geometrii przedkuwek miały duży wpfyw na rozkład sił w matrycach. Wyniki obliczeń były bardzo pomocne w określeniu takich parametrów procesów, przy których siły poprzeczne okazały się najmniejsze.