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Hydraulic shock absorbers of train bogie
Odehnal, Lukáš ; Jeniš, Filip (referee) ; Kubík, Michal (advisor)
This bachelor thesis mainly deals with design solutions of adaptive dampers used on railway vehicle bogies. The first part gives a general overview of the topic. The main part discusses current designs of adaptive dampers that have already been tested. Final part of the thesis compares the designs including their determining parameters in order to obtain a large enough sample to contribute to the development of a new, electronically controlled damper at the VUT in Brno.
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Design of semiactive suspension for mountain terrain bike
Mráz, Kryštof ; Kubík, Michal (referee) ; Strecker, Zbyněk (advisor)
This Bachelor Thesis is focused to design semiactive suspension of mountain bike using MR damper. In research part of thesis is summarised knowledge about passive and semiactive suspension of mountain bikes and about MR dampers. Behaviour of suspended front fork was simulated using virtual dynamic model which was created in graphic environment MATLAB Simulink. Semiactive algorithms Skyhook and modified Groundhook and for comparison also passive settings are simulated. According to results of these simulations is designed semiactive suspension with MR damper which has effect to stabilising contact force of front wheel and therefore increases safety of rider.
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Pneumobile dynamometer design
Fritscher, Matyáš ; Kubík, Michal (referee) ; Jeniš, Filip (advisor)
This bachelor thesis concerns design of measuring station with a dynamometer for a racing pneumobile developed by a student team. The aim of this device is to simplify the process of tuning of the vehicle and to make it more precise. At the beginning of the work, there is a research of current commercial solutions of dynamometer stations. Then, while choosing a suitable brake, there is an evaluation of the possibility of repurposing an old brake, given by the university for this project. After verifying that it meets the necessary requirements, there are several concept solutions presented. For the selected concept, with a specific design for this vehicle, there is a complete design solution including safety analysis of selected nodes.
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Study on wear of material in contact with MR fluid
Žáček, Jiří ; Vimmr, Jan (referee) ; Kubík, Michal (advisor)
This paper is focused on MR dampers and its critical parts in term of damper`s durability, which seems to be a piston-rod seals, and it should find an ideal material combination of seal and MR fluid for increasing the damper`s life. The tests were conducted in modified pin-on-flat configuration, which was supposed to be more suitable for laboratory testing. There was tested and compared a suitable material for seals, like PTFE, NBR, SBR of polyurethanes. The article is also focused on MR fluids and its contribution to seal`s wear. The impact of particle concentration, wear of MR fluid and effect of modification of MR fluid was tested. It showed up, that the best material for seal is H-PU95FDA. The effect of particle concentration is negligible on seal`s wear, while effect of modification and wear of MR fluids are significantly higher.
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Design of low-pressure magnetorheological damper
Mareš, Jan ; Žáček, Jiří (referee) ; Kubík, Michal (advisor)
This bachelor thesis deals with the problem of the limited lifetime of sealing elements inside high-pressure magnetorheological dampers. The lifetime could be extended by the low-pressure damper design, which is also the aim of this thesis. The proposed design achieves low-pressure operation thanks to the MR foot valve inserted between the damping piston and floating piston of the air chamber. This foot valve also contains a blow-off check valve. For simplicity and to reduce the upfront costs of the testing prototype, the damper was designed by modifying an existing single-tube high-pressure MR damper available at FSI VUT. The contribution of this thesis is the experimental evaluation of check valve function in MR fluid. Valve exhibits asymmetrical behaviour and closes rapidly. The main outcome is the design of a low-pressure single-tube MR damper. It is expected that operation at lower pressures will extend the lifetime of sealing elements which may lead to broader implementation of MR dampers.
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The development of fail-safe magnetorheological damper
Hašlík, Igor ; Růžička, Bronislav (referee) ; Kubík, Michal (advisor)
This diploma thesis deals with an engineering design of a fail-safe magnetorheological (MR) damper capable of semi-active control. The first part of the thesis is devoted to the current state of knowledge of fail-safe MR dampers and permanent magnets contained in these dampers. The next part contains an engineering design of a fail-safe MR damper, made using FEM simulations, and its subsequent testing in terms of magnetic and hydraulic properties. Finally, a design of a fail-safe MR damper with fast response time was made and simulated using verified FEM analysis. Fast response time is ensured by limiting the generation of eddy currents in the piston core by grooving.
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Numerical hydraulic model of active zone in magnetorheological damper
Regner, Dominik ; Roupec, Jakub (referee) ; Kubík, Michal (advisor)
This bachelor thesis deals with the comparison of analytic hydraulic model and numerical models of MR damper‘s active zone. Next is the study of the influence of annular gap geometry and rheological properties of MR fluid to damper‘s performance. In the first part, there is the summary of knowledge about MR dampers and used numerical approaches. Next part describes the creation of models and in the final part there is the comparison of these models and validation is completed with data from the real damper. Also, there is an evaluation of results about changes of geometry and rheology.
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Design of stand for magnetic seal testing
Švec, Jaroslav ; Kubík, Michal (referee) ; Roupec, Jakub (advisor)
This bachelor thesis deals with design and construction of mounting board of stand for magnetic seal testing and with control of mounted asynchronous motor using inverter. In this thesis was done analysis of ways of controlling three-phase asynchronous motor with inverter, analysis of sensors for measuring testing conditions and analysis of modular aluminium profile systems. There was created three conceptions of mounting board from which the most suitable was chosen to be built. From ways of control was chosen the most convenient way. The result of this thesis is stand for magnetic seal testing, using which will be possible to gain new knowledge of magnetic sealing and its future use.
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Testing the magnetic seal
Pavlíček, Dušan ; Sabo, Karol (referee) ; Kubík, Michal (advisor)
Using magnetic fluids were implemented new devices and new technologies that are convenient alternative to existing, thanks the exceptional properties of these liquids. Currently does not exist suitable device for testing magnetic seal, and therefore this thesis deals the design of the stand for testing a magnetic seal.
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