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Design of a test condition for determining the wear at the contact of a railway wheel and rail
Rec, Matouš ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This diploma thesis focuses on the issue of a wear of a railway wheel and a rail. The wear of the components depends on a number of parameters including the contact stress, the contact pressure and the contact surface dimensions. Among the factors determining these parameters belongs primarily the wheel driving gauge, the rail profile and the load of the contact area. Furthermore, the material from which the wheels and rail are made, the roughness and hardness of the functional surfaces and the residual stress in the material have a significant impact on the wear. All the parameters mentioned above are designed for the production of the railway wheels and rails and therefore they meet the standards for the production of these components. However, the existence of the changeable parameters has also a significant impact on the wear. These parameters include the presence of contaminants, or lubricants in contact, the changing driving gauge due to the wear, the slip ratio or the friction coefficient. With the wear being an inevitable process during the application it cannot be eliminated but only controlled. Applying the lubricant into the contact when passing through the arc in order to achieve an ideal coefficient or the maintenance grinding for restoring the driving gauge can serve the purpose. If properly optimized, the importance of the wear research lies in the financial savings. Being the crucial factor for optimization of the intervals between the maintenance grinding, the research is also beneficial. A high-quality wear prediction can be seen as the key field in order to increase the safety of the railway vehicles operation as well. Therefore, the wear research is made using several methods, such as the computational models, the multi-body dynamics software and the technical experiments. This thesis introduces a conceptual design of the test, enabling the wear research via experimental approach. The final device is capable of a simulation of both volume and fatigue wear during the states the railway wheel and railway undergo including riding on the straight track, passing through an arc or a wheel slip during braking.
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Rail materials and profiles in rail transportation
Svobodová, Anežka ; Kvarda, Daniel (referee) ; Galas, Radovan (advisor)
This bachelor’s thesis is focused on the issue of the choice of rail materials and profiles. The aim is to give a comprehensive overview of the current situation in Czech Republic and some other foreign countries. The first part is dedicated to rail steels with description of structure, current usage and indication of the scopes of consecutive development. In the second part, there are described the most frequent profiles, their history and the current state. This thesis includes also discussion part which compares current problems and requirements that can be significant to some possible research.
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Evaluation of the Trial Section for Under Sleeper Pads
Murínová, Klára ; Langer, Vojtěch (referee) ; Plášek, Otto (advisor)
Under sleeper pads (USP) are elastic pads on underneath surface of the sleeper. Their main advantage is reducing of stress in track bed, slowing down a deterioration of track quality, life extension of railway track and reducing life cycle cost. There are three trial track sections in the Czech Republic in which are USP used. The influence of the USP is continuously monitored. The bachelor thesis is focused on the Ústí nad Orlicí trial track section. This thesis describes measurements of the track level by the precise levelling method and measurements of the stress in track bed carried out in the 2016 and 2017 and their evaluation and comparison with previous measurements in the 2015.
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Off-board systems for top-of-rail lubrication
Málek, Jan ; Kvarda, Daniel (referee) ; Galas, Radovan (advisor)
This bachelor’s thesis is focused on rail off-board lubrication system. The main part of this thesis is explaining of function and design few certain lubrication systems. In this thesis are explained aspects of wheel-rail contact, such as types and parts of rail, adhesion, slip, creep–traction diagram. Another part of this thesis is description of few certain lubrication system for top of rail and gauge face application. In this thesis are explained product of major companies of friction management industries such as SKF-Lincoln, Whitmore, Loram. Additional part of this thesis speaks about usage and development of this devices in Czech Republic. Output of this thesis is conclusion about advantages and disadvantages these certain devices.
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Upgrading of Lipová Lázně Railway Station
Kopecká, Denisa ; Mazel, Lukáš (referee) ; Svoboda, Richard (advisor)
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.
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Design of corrugation measuring device
Valena, Martin ; Omasta, Milan (referee) ; Galas, Radovan (advisor)
This bachelor thesis describes the development of experimental corrugation measuring device. In the first part, mechanisms of corrugation formation and classification of corrugation, together with an analysis of measuring devices are described. According to the analysis, several design configurations were developed. The final variant is described in detail, together with the calculations. The output of this bachelor thesis includes complete technical drawings and price estimation.
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The effect of climate conditions on wheel-rail contact adhesion
Nohel, Rostislav ; Horák, Zdeněk (referee) ; Omasta, Milan (advisor)
Presented master’s thesis is focused on the experimental research of influence of climate conditions on wheel-rail adhesion, where climate conditions are meant two parameters: ambient air temperature and air humidity. These parameters always affect wheel-raid contact and their values change significantly during the year. For presented experimental research was used tribometer Mini Traction Machine (MTM) in configuration „ball on disc“. For determination of influence climate conditions was first found out the influence of air humidity on adhesion at certain temperatures, which varied between (1 to 50) °C. These experiments were performed for two types of discs, where one disc was exposed to leaf extract contamination. After that was assembled influence of both parameters (air humidity and ambient air temperature) on adhesion in the form of a 3D map, where were distinctioned states, when condensation has occured and when didn‘t. Obtained results in this thesis will be used for optimalization of rail vehicle control systems.
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Upgrading of Uničov Railway Station
Šafář, Zdeněk ; Vacek, Josef (referee) ; Svoboda, Richard (advisor)
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.
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Evaluation of under sleeper pads influence in the test section in Planá nad Lužnicí railway station
Švanda, Tomáš ; Langer, Vojtěch (referee) ; Hruzíková, Miroslava (advisor)
Under sleeper pads (USP) are elastic layers positioned on the bottom surface of sleepers. Their aim is to slow down a deterioration of track geometrical parameters and reduce track maintenance costs. Three test sections with under sleeper pads have been built on the railway network in the Czech Republic. The effect of the under sleeper pads is continuously monitored. The height level of rails is measured by precise levelling. This thesis is focused on the Planá nad Lužnicí test section. It describes the precise levelling measurement in the 2015 and its evaluation and comparing with previous measurements. Furthermore track recording car measurements were evaluated.
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