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Experimental study of friction modifiers in rail transportation
Knápek, Jiří ; Dzimko, Marián (referee) ; Galas, Radovan (advisor)
The adhesion in the wheel-rail contact can be effectively controlled by using the friction modifier. Adhesion control can reduce excessive wear of the contact bodies or noise. The essence of this diploma thesis is to determine the optimal amount of friction modifier in wheel-rail contact depending on the climatic and operating conditions. For experimental study of the behavior of the friction modifier, the twin-disc device is used. Twin-disc simulates and controls the most important operating parameters such as speed, slip, attack angle or contact pressure. On the basis of these findings, the off-board top-of-rail lubricator system was designed. This system controls the amount of friction modifier according to current climatic and operating conditions.
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Design of Experimental Stand for the Study of Railway Vehicles Sanding
Galas, Radovan ; Hruška, Marek (referee) ; Šperka, Petr (advisor)
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.
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Effect of Active Vehicle Safety in the Prevention of Road Accidents
Franc, Šimon ; Frič, Jindřich (referee) ; Panáček, Vladimír (advisor)
This diploma thesis focuses on effects of active vehicle safety on the prevention of traffic accidents. In the introductory section, the term of active safety is defined and divided into four categories. In next four chapters, the particular elements of active safety are described in more detail and some selected elements are described in depth. Chapter seven includes a questionnaire; it enquires opinions of people about some of the elements of active safety. Practical road tests were conducted as part of this work. Theirs description and evaluation are in the last chapters.
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Analysis of contaminants in wheel and rail contact
Straka, Tomáš ; Galas, Radovan (referee) ; Kvarda, Daniel (advisor)
Wheel/rail contact is significantly influenced by so called third body – contaminants. Aim of this bachelor’s thesis is to analyse those contaminants in the contact and to create a brief overview. Short introduction into problem of wheel/rail contact is included, followed by description of main contaminants occurring in the contact. This thesis may be used as introduction into contamination of wheel/rail contact problem.
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Influence of friction modifiers composition on traction in wheel-rail contact
Kvarda, Daniel ; Hartl, Martin (referee) ; Galas, Radovan (advisor)
Friction modifiers are a new effective way to control adhesion in wheel and rail contact. The aim of this diploma thesis is experimental study of the influence of the constituents of water based friction modifier on adhesion. Measurement of the adhesion behavior for different friction modifier compositions is carried out on a ball–on–disc laboratory device creating point contact. The introductory part of the experiments describes the effect of individual components on adhesion. Subsequently, combinations of different friction modifier compositions are tested. In conclusion, selected compositions are used for wear tests. The results obtained show that the performance of friction modifiers is greatly influenced by evaporation of base medium.
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Analysis of the effect of friction modifiers composition on adhesion and noise in rail transport
Suchomel, Ondřej ; Galas, Radovan (referee) ; Klapka, Milan (advisor)
The aim of this bachelor thesis is experimental study of influence of composition of water based friction modifier on adhesion and sound pressure level. Experiments are carried out on twin-disk device. Introductory experiments are conducted to determine the conditions for further experiments. The experiments of the individual components follow, and the various friction modifier compositions are tested. From the results, it is obvious that a significant influence on the reduction of adhesion coefficient and sound pressure level has solid lubricant.
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Development of a tribometer for the adhesion measurement on a real rail
Vodehnal, Michal ; Polach, Pavel (referee) ; Omasta, Milan (advisor)
The submitted master’s thesis describes the development of a tribometer used to measure the adhesion of a real rail. The thesis contains an overview of the basic terms concerning wheel and rail contact. Following that, there is an overview of devicesthat are able to measure the adhesion on a real track. The author's solution includes a design of the tribometer, the proposed measurement methodology and also a description of the individual components. The result of this thesis is a functional device, verified in laboratory conditions and on a real track.
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Analysis of contaminants in wheel and rail contact
Straka, Tomáš ; Galas, Radovan (referee) ; Kvarda, Daniel (advisor)
Wheel/rail contact is significantly influenced by so called third body – contaminants. Aim of this bachelor’s thesis is to analyse those contaminants in the contact and to create a brief overview. Short introduction into problem of wheel/rail contact is included, followed by description of main contaminants occurring in the contact. This thesis may be used as introduction into contamination of wheel/rail contact problem.
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Development of a tribometer for the adhesion measurement on a real rail
Vodehnal, Michal ; Polach, Pavel (referee) ; Omasta, Milan (advisor)
The submitted master’s thesis describes the development of a tribometer used to measure the adhesion of a real rail. The thesis contains an overview of the basic terms concerning wheel and rail contact. Following that, there is an overview of devicesthat are able to measure the adhesion on a real track. The author's solution includes a design of the tribometer, the proposed measurement methodology and also a description of the individual components. The result of this thesis is a functional device, verified in laboratory conditions and on a real track.
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Analysis of the effect of friction modifiers composition on adhesion and noise in rail transport
Suchomel, Ondřej ; Galas, Radovan (referee) ; Klapka, Milan (advisor)
The aim of this bachelor thesis is experimental study of influence of composition of water based friction modifier on adhesion and sound pressure level. Experiments are carried out on twin-disk device. Introductory experiments are conducted to determine the conditions for further experiments. The experiments of the individual components follow, and the various friction modifier compositions are tested. From the results, it is obvious that a significant influence on the reduction of adhesion coefficient and sound pressure level has solid lubricant.
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