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Design of dual-chamber pneumatic spring
Pantůček, Michal ; Roupec, Jakub (referee) ; Macháček, Ondřej (advisor)
This thesis is engaged in the design of a pneumatic spring which will be useful for a design of a strut intended for cosmic applications. The design will be supported with an analytic calculation which to be subsequently verified by means of experiments, however, those reach beyond the scope of this thesis. The spring will be a part of a strut with adjustable shock damping. For this reason it is desirable for the spring to have the lowest passive resistances occurring mainly during sealing mutually moving parts. For the spring they are the piston, the piston rod and the cylinder. On the theoretical level the thesis should explore the possibility of replacing conventional sealings by unconventional ones and possibly determine the influence upon dynamical behaviour of the spring where the piston would not be sealed at all.
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The study of MR fluids sedimentation
Berka, Pavel ; Vimmr, Jan (referee) ; Roupec, Jakub (advisor)
This diploma thesis investigates the accelerated sedimentation of the magnetorheological fuids (MRFs) using centrifuge. Experiments are carried out at room temperature as well as at higher temperatures (40°C, 60°C and 80°C). The development of the new improved measuring device for the sedimentation evaulation is described. Magnetic components of the device were designed using FEM analysis. Newly designed device is verified. To accomplish the experiments at the high temperatures the new heated chamber for experimental centrifuge is designed and constructed. In the next part of the work full experiment of the accelerated sedimentation is performed. At final the empirical model of the sedimetation velocity for various accelerations and temperatures is synthesized.
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Design and analysis of racing pneumobile frame
Jelínek, Josef ; Roupec, Jakub (referee) ; Ranuša, Matúš (advisor)
This bachelor thesis reacts to the changes in the Aventics Pneumobil competition in the new season and proposes a solution to eliminate problems affecting drivability of the vehicle which were identified previously. Part of this thesis aims to analyze recent Institute of machine and industrial design at Brno University of Technology’s pneumobile vehicles frames and their problems. It also contains a whole new frame designing process. There are basic informations about the Aventics Pneumobil competition and its rules connected to this thesis. The process of designing a new frame requests a lot of input quantities of the vehicle. A lot of them were unknown and had to be set in order to gain the desired vehicle properties. The main part of the thesis is the construction part. A detailed CAD model is designed on the basis of chosen vehicle concept. It is then exported into a Finite element software for a strength analysis. All results are summarized in the conclusion and the next procedure is recommended.
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The study of sedimentation of MR fluids for space applications
Vančurová, Martina ; Strecker, Zbyněk (referee) ; Roupec, Jakub (advisor)
This bachelor thesis deals with experimental determination of the effect of iron particle size on the sedimentation rate of magnetorheological (MR) fluids. MR fluids from three producers are examined here: Liquids Research Limited (Great Britain), HaoHua (China) a LORD Corporation (USA). Particles describing the effect of MR fluids’ different attributes on their sedimentation are summarized in an overview of current knowledge. The development of the Matlab script, that detects and measures the size of particles in the input electron microscope images, is presented. The particles are also measured manually in some images, which is partly used as a reference measurement for the developed script. The particle size measurement results are then compared with the sedimentation behavior of examined MR fluids.
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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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Limiting and Degradation Processes of Magnetorheological Suspension Dampers
Roupec, Jakub ; Bauer, František (referee) ; Ondrůšek, Čestmír (referee) ; Dobeš, Petr (referee) ; Mazůrek, Ivan (advisor)
This work deals with the research of degradation of magnetorheological (MR) fluid during long-term loading under conditions that correspond to the real load in the linear MR devices such as dampers. The behaviour of MR fluid is described by a Bingham model of viscoplastic fluid. The parameters of this model are the yield stress and viscosity. Their values are determined by the shear rate from 1 to 2,8104 s-1. Results of durability tests show a significant decrease in viscosity of MR fluid, a gradual increase in yield stress in the off-state and a significant decrease in MR effect. The paper also described the effect of temperature on these parameters and there is also designed a method of non-assembly diagnostic of the MR fluid state in the damper using the "rate of pulsation."
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Design of magnetorheological clutch.
Nováček, Vladislav ; Dočkal, Aleš (referee) ; Roupec, Jakub (advisor)
This thesis deals with the design of the magnetorheological (MR) clutch. The extensive literature research with particular conclusions to each design variant of MR clutches or brakes has been done in the first part of the thesis. The second part of the thesis describes the design of the actual MR clutch based on the results of the analytical calculation of the magnetic circuit. Finally, the experiments verifying the function of the key segments of the clutch, and the whole clutch are summarized in the third part of the thesis.
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Optimisation of gear ratio for racing cars
Bém, Pavel ; Roupec, Jakub (referee) ; Mazůrek, Ivan (advisor)
Pavel BÉM Optimisation of Gear Ratio for Race Cars DW, IAE, 2008, pp. 62, fig. 69. At first I labellig problems about gearboxes than, I review dataloggers for racing cars using now. I create model of dynamic simulating car move during at akcelerating and decelerating on choice track. I create program analyzating data from telemetry and applicated dynamic model to optimisation gears ratio.
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Sedimentation of MR fluid at the start of new space lanucher
Berka, Pavel ; Strecker, Zbyněk (referee) ; Roupec, Jakub (advisor)
This bachelor thesis deals with sedimentation behavior of magnetorheological fluid exposed to acceleration 1-6 G. That simulates start of a space launcher. Main goal of this work is to bring new knowledge of MR fluids behavior. Experiment of accelera-ted sedimentation as well as the long term sedimentation is presented, including new method and measuring device developed to measure the sedimentation, in order to compare different commercial MR fluids. Results from this work will be used in development of the new semiactive dum-ping system for carrying load in ESA new space launcher.
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