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Conceptual design of a manned mobile lunar habitat (vehicle)
Mikeš, Adam ; Porteš, Petr (referee) ; Šálený, Vratislav (advisor)
Bakalářská práce se zabývá konstrukcí lunárního vozidla. V práci jsou popsány případy reálného použití lunárního vozidla. Dála se práce zabývá konstrukcí podvozku lunárního vozidla. Úkolem konstrukční části je návrh ideálního podvozku pro měsíční povrch s důrazem na hmotnost a jednoduchost provedení. Konstrukční řešení jsou následně podrobena analýze za účelem dosáhnutí efektivních výsledků.
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Design of suspension for an electric off-road motorcycle
Hlaváč, Pavel ; Hejtmánek, Petr (referee) ; Míša, Jiří (advisor)
This master thesis deals with the design of suspension for an electric off-road motorcycle. The aim is to determine the optimum damping force and spring stiffnesses for a motorcycle with given parameters for different rider weights. Some input parameters had to be measured, such as tire stiffness and damping, fork and shock damping of the same type of motorcycle. Other damping forces were created using the measured ones to cover wider range of damping ratios. Then these forces and spring stiffnesses were tested in quarter car and half car models to evaluate the changes in suspension setting on rider comfort a ride safety. Then the ideal damping forces and spring stiffnesses for an electric off-road motorcycle are determined from the simulations performed.
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Drop Test of Airplane Suspension - Springing and Damping
Fousková, Karolína ; Hejtmánek, Petr (referee) ; Blaťák, Ondřej (advisor)
This thesis discusses aircraft landing gears, describes the basic requirements placed on them, and outlines their primary classifications and construction, including damping and suspension methods. It describes the drop tests used in aviation and the methods of their evaluation, demonstrating the results of selected tests through simulation analysis. The thesis also includes the design concept of the testing equipment.
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Electronic Control Systems of Vehicle Springing and Damping System
Ladatkin, Vladislav ; Hejtmánek, Petr (referee) ; Blaťák, Ondřej (advisor)
The bachelor's thesis explores the topic of electronic suspension and damping control systems of vehicles. Modern suspension systems make it possible to solve the existing conflict between ride comfort and vehicle handling by reacting to changing driving conditions in real time. The theoretical part of the thesis is dedicated to a detailed description of current electronic control systems, including the construction of springs, shock absorbers and control valves. The practical part focuses on the design of a rotary adjustable damper valve for an adaptive suspension system. The results of this work contribute to a better understanding of modern technologies in the field of vehicle suspension and damping control.
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Vehicle Hydropneumatic Unit
Koudelka, Roman ; Hejtmánek, Petr (referee) ; Blaťák, Ondřej (advisor)
This diploma thesis, following the bachelor's thesis, is devoted to the gas-liquid unit of a vehicle, as the central element of hydropneumatic suspension. The aim is to dimension and construct this component and integrate it together with other elements into a complex suspension system. Based on possible forms listed in the research section, regarding to current development trends, the form of the unit is chosen. The practical part begins with simulations comparing a hydropneumatic with a conventional suspension system. After solving this issue, it is possible to proceed to the dimensioning of the basic parameters of the unit and then to its construction, respecting the relevant strength calculations. The last step is to build a conceptual design of the whole hydropneumatic suspension system.
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The modal damping ratio analysis of the mechanical part using the OMA method
Sodomka, Tomáš ; Lošák, Petr (referee) ; Houfek, Lubomír (advisor)
In one of the first hours of study at the Institute of Mechanics of Bodies, Mechatronics and Biomechanics, the author of this work received three basic recommendations regarding measurement: 1) Do not measure! 2) If you measure, do not repeat the measurement!! 3) If you repeat the measurement, do not compare the measurements!!! However, this thesis boldly violates all three recommendations. In the introductory theoretical part, it briefly introduces the vibration of multi-degree of freedom damped systems and describes experimental ways of determining the modal damping. It also summarizes the Operational Modal Analysis (OMA) approach, explains the principle of the FDD method, and introduces EFDD (Enhanced Frequency Domain Decomposition) method which allows to determine not only natural frequencies and shapes as FDD does, but also modal damping of the shapes. A script in Matlab environment for processing vibrations using EFDD method is one of the thesis outputs. The script is first tested by computational model, where a model system with known damping is tested and damping is determined by the script. Subsequently, the work moves to the actual measurement of the real system - a bonded bar which is analysed by Experimental Modal Analysis and OMA, while the second variant uses commercial EFDD method (Brüel a Kjr company) and programmed script. In the conclusion of the thesis the damping results are compared to each other. The diploma thesis continues in Ing. M. Pop’s thesis – Modal Analysis Experimental Method Verification. From this work a part of measured data is taken. Specific cases of data use are always listed in the appropriate section of the text.
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Development of transaxles in automobiles
Kubiš, Vojtěch ; Kaplan, Zdeněk (referee) ; Píštěk, Václav (advisor)
This bachelor thesis is concerned of development of transaxles in automobiles. Overview of types of axles is mentioned here as well as their working principles. Attention is also given to suspension and damping with description of how it works. In this thesis are described solutions of selected cars suspensions.
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Effect of Shock Absorber on Vehicle Limits
Jurka, Adam ; Blaťák, Ondřej (referee) ; Hejtmánek, Petr (advisor)
The aim of this master’s thesis is to evaluate the effect of shock absorber on vehicle limits. At the beginning of the thesis, shock absorber properties were described. Then computational model was created and manoeuvres for shock absorber behaviour were defined. Created mathematical model is based on quarter model of a car and excitation in form of road with a random profile is an essential part of the model. This model was used for evaluation of heave. After heave analysis, shock absorber behaviour during drive was investigated. Drive conditions were defined as set of handling manoeuvres. For the drive investigation, complete multibody virtual model of racing car was used. Based on drive investigation analysis, optimal damping characteristics for each manoeuvre were found. Furthermore, each optimal characteristic was compared for different manoeuvres. Obtained results were compared. As a conclusion, compromise damping characteristic was suggested with the aim to fit the combination of all defined drive conditions. Final part of the thesis was aimed at validation of the computational model. Data measured during real drive were used as an input for this validation.
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Design of optical amplifier
Somora, Rastislav ; Číž, Radim (referee) ; Slavíček, Karel (advisor)
This Bachelor's thesis deals with design and construction of support circuits for a modern optical amplifier the SOA. In the first chapter, optical transmitting medium with its physical properties and types of used cabels is described. The overview includes a list of optical cables, their damping properties and parasitic effects which can occur durring comunication. Next chapter is focused on the optical signal sources used in modern data networks, describes their internal structure and physical essence. Third chapter is dedicated to designing the optical amplifier with the SOA circuit. It focuses on the right choice of parts, their arrangement and layout of the design. Last chapter deals with set up, calibration and control of the optical amplifier module.
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Resonance and damping behavior of lattice structures produced by Selective Laser Melting
Lagiň, Adam ; Čížek, Petr (referee) ; Koutný, Daniel (advisor)
In reaction to the uptrend of additive manufacturing of lightweight structured metallic parts, this diploma thesis is focused on the resonant and damping behavior of micro-truss lattices produced by Selective Laser Melting (SLM) technology. Micro-truss structures already found usage in various types of optimizations. Therefore, the optimization of resonance or damping could be also assumed as possible. For this purpose, several finite element analysis approaches were used, including the referent solid element model and simplified beam models. Obtained results were verified experimentally via pulse modal analysis. Material and mechanical properties of samples for FEA results and experimental results comparison were unified through secondary experiments. The main goal of this research was to explore the behavior of resonance and damping of structures when their elementary parameters are changed. The results from both, numerical and experimental approaches confirm that the eigenfrequency and the damping ratio of the structure can be affected by the change in the truss diameter, cell size, or type of structure. The work also presents the successful methods for simplified beam model optimization, which guarantees its high precision in the wide field of tested samples. This newly obtained knowledge creates a comprehensive overview of micro-truss structures, which can be used for the conscious design of ultra-light parts with the required eigenfrequency and damping ratio.
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