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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Konstrukce stacionární jednotky pro mazání hlavy kolejnice / Design of wayside unit for top-of-rail lubrication

Valena, Martin January 2019 (has links)
This master’s thesis describes design and realization of a wayside unit for top-of-rail lubrication (TOR). TOR lubricant application causes wear reduction and lower noise emission. Firstly, patent analysis was provided and critically evaluated according to which requirements for developed device were specified – accurate dosage of small lubricant volume and high repeatability. On the basis of concept design, an experimental rig was created and used for lubricant application verification and spray lubrication parameter identification. Acquired results are considered in the final design of wayside unit with a technical facility. Two utility models were created within this master’s thesis.
12

Testování výkonnosti maziv pro kolejovou dopravu / Testing of Rail Lubricants Performance

Tomčová, Renata January 2021 (has links)
Top-of- rail lubricants are an effective way to control adhesion, reduce contact wear and noise in rail transport. However, despite the widespread use of these lubricants, there is currently no standard defining how to test and evaluate their performance. This work aims to develop a methodology for testing top-of-rail lubricants in a laboratory environment using a tribometer in a ball-on-disk configuration. At first, important operational parameters of experiments are analyzed and experimentally tested. These are mainly wear-in and run-in, method of application, roughness and geometric parameters of contact bodies. The result of this work is a testing methodology that guarantees good repeatability and reliability of results. In the last part of this work, the methodology is verified using commercial top-of-rail lubricants.
13

Minimalizace zbytkového napětí při dochlazování válcovaných profilů / Minimization of residual stresses for rolled long products

Kubík, Petr January 2009 (has links)
This thesis deals with simulation of cooling of rail during its passing through cooling device which has been designed by the heat transfer and fluid flow laboratory. Inputs of the computational model have been set up to get best possible correspondence between outputs of the computational model and results of experimental measurement. The solution with using of model of austenitic stainless steel is provided in first part of the thesis. The solution with considering model of carbon steel is performed in next part. Using of model of carbon steel allows including evolution of latent heat during phase changing. A fields of residual stress has been calculated for different cooling conditions in the last part of this thesis.
14

Konstrukce experimentálního zařízení pro studium pískování kolejových vozidel / Design of Experimental Stand for the Study of Railway Vehicles Sanding

Galas, Radovan January 2013 (has links)
Presented master’s thesis describes the design and the implementation of an experimental device used for the study of tribological aspects of wheel-rail contact. In this work, the reader will first learn the fundamentals such as adhesion, slip, traction curve, etc. Subsequently, the work is describing devices that are used for the study of wheel-rail contact around the world. This section is followed by the author proposed solution. The result is a twin disc device in the scale of 1:3. The device allows determining traction characteristics for different environmental conditions (presence of water, sand and oil in contact for different temperatures) and various operating parameters (contact pressure and speed). A part of this work are also the validation experiments and complete design documentation.
15

Experimentální výzkum pískování v kontaktu kola a kolejnice / An Experimental Research of Sanding in Wheel/Rail Contact

Machatka, Martin January 2014 (has links)
Presented master's thesis is focused on the experimental research of the sanding parameters in order to improve adhesion in the contact between wheel and rail. Sanding is the application of the sanding material directly in the wheel/rail contact. It is still common, most effective and traditional way how to deal with low adhesion problem, which is mainly caused by environmental contaminants. Research is important for the better understanding of the sanding process and also provides data, which are necessary for it's optimization and efficiency improvement. Newly developed twin-disc machine was used to carry out the presented experimental research. The influence of common contaminants on the adhesion is investigated, considering various operating parameters. Different amount of the applied sand is used to increase adhesion in the contaminated contact at various slip and rolling speed. Results show, that there is the amount of the sand, from which no significant adhesion increase occur. Obtained findings and the results presented in this thesis will be used to optimize sanding system, which will contribute to reduce cost associated with sanding and low adhesion.
16

Rekonstrukce železniční stanice Uničov / Upgrading of Uničov Railway Station

Šafář, Zdeněk January 2017 (has links)
This thesis focuses on the reconstruction design of Uničov railway station. The aim was to create a solution which would satisfy both traffic and passenger requirements. The design puts an emphasis on a compliance with applicable laws and standards, simplicity and usefulness. New constructions were designed for maximum safety. Railway station accessibility for disabled persons played an important role in the design. In comparison with the original state, the permissible line speed was increased and new platforms and drainage system were designed.
17

Výpočtové modelování dynamických projevů v kontaktu kola a kolejnice s obecnou geometrií kontaktních povrchů / Numerical Simulations of Dynamic Loads in Wheel-Rail Contact with Shape Irregularities

Jandora, Radek January 2012 (has links)
During life of railway vehicles, shape irregularities develop on wheels and rails because of wear. The shape irregularities then affect forces in wheel-rail contact and cause further damage of contact surfaces, vibrations and noise and increase risk of derailment. A numerical simulation of railway vehicle motion with more details on contact surfaces geometry was created to investigate dynamic contact loads in wheel-rail contact. A variety of methods can be used to evaluate forces in rolling contact, the method chosen for this study was algorithm CONTACT based on boundary element method. Four studies are presented in this papers: contact loads from a wheel with a flat and with a wavy tread pattern, loads on wavy rail and load in a curve. The first three studies investigated effects of existing wear patterns, the last one looked for cause of common wear pattern developing on rails. Results of the studies with worn components used showed that the worst kind of shape irregularities is a flat present on wheel. This type of shape cause loss of contact and following impacts. The study of ride in curve showed that cause of high wear in curves, especially those with small radii, is caused by vibration of wheelset. This vibration is then caused by different length of inner and outer rail and wheels travelling along a different path.
18

Rekonstrukce železniční stanice Lipová Lázně / Upgrading of Lipová Lázně Railway Station

Kopecká, Denisa January 2018 (has links)
The master's thesis deals with reconstruction design of Lipová Lazně railway station. The main goal is to design new platforms suitable for passengers with reduced mobility and orientation and valid standart. Another goal is to increase line speed. Part of the thesis includes modifications of railway superstructure, substructure and drainage system of the station.
19

Modernizace trati Brno – Přerov v okolí Vyškova pro rychlost 200 km/h / Modernization of Brno - Přerov railway line in Vyškov area for speed 200 km/h

Hašek, Jan January 2013 (has links)
The objective of this master´s thesis is a design of modernization of railway line no. 300 Brno – Přerov in Vyškov area and its vicinity for speed 200 km/h. The track section is located between railway station Luleč and Ivanovice na Hané. The track is designed in two variants. The first variant is proposed keeping railway line through Vyškov railway station including necessary modification of the railway station. The second variant suggests keeping track outside Vyškov and a connection with the railway station by bridging is designed.
20

Vyhodnocení geometrických parametrů koleje s podpražcovými podložkami / Assessment of Geometry Parameters of Track with Under Sleeper Pads

Škovranová, Michaela January 2013 (has links)
The diploma thesis applies to under sleeper pads. It researches thein using and benefits in foreign railvway authorities. Further it assesses track geometrical parameters in the trial track section with under sleeper pads in track Havlíčkův Brod - Okrouhlice and in the railway station Planá nad Lužnicí. There were evaluated measurements of vertical alingnment rails by precise leveling and deviations of track geometrical parameters measured by track meusuring car in the diploma thesis.There is expressed an conclusion about the impact of under sleeper pads on track geometric data in the thesis.

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