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Powder feeder design for multi-material metal 3D printing
Kulda, Martin ; Malý, Martin (referee) ; Grygar, Filip (advisor)
This bachelor thesis deals with the issue of multi-material metal 3D printing, specifically the method of material transfer between containers and powder application on the work surface. The aim of this bachelor thesis is to design, implement and test a dispensing device for refilling the coating head for multi-material metal 3D printing and to optimize the design of the coating head itself. Based on the research, conceptual designs were developed and subjected to a series of tests. The results of these tests led to the development of a specific design solution, including both the coating head and the dispensing device. These solutions were subsequently implemented and tested for key functions. The implemented solution enables reliable material transfer between containers as well as to the work surface. It also allows easy and quick exchange of the magazines themselves in case of printing a different set of materials.
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Description of fatigue behavior of additively manufactured polymer metamaterial structure
Helešicová, Petra ; Ševeček, Oldřich (referee) ; Trávníček, Lukáš (advisor)
Metamateriály jsou v posledních letech velmi často zkoumanou oblastí, jelikož umožňují přizpůsobení mechanických vlastností vyráběných součástí, které není možné získat s využitím konvenčních materiálů. Aby bylo možné metamateriály bezpečně využívat v provozu, je nutné popsat jejich chování při zatěžování. Prezentovaná diplomová práce je zaměřena na popis únavového chování 3D tištěné polymerní metamateriálové struktury. Práce je rozdělena na teoretickou a praktickou část. V teoretické části je provedena rešerše metamateriálů a jejich rozdělení, poté rešerše metod 3D tisku vhodných pro polymerní materiály a nakonec jsou představeny základy mechanického chování polymerů. V praktické části jsou postupně prováděny kroky pro určení odhadu únavové životnosti uvažované metamateriálové struktury pomocí čtyř kritérií. Pomocí experimentálních testů jsou naměřeny mechanické vlastnosti uvažovaného materiálu, které jsou vloženy do vytvořeného numerického modelu. Okrajové podmínky a zatížení modelu jsou zvoleny tak, aby odpovídaly reálným podmínkám při zatěžování. Numerický model je využitý pro určení kritických lokací ve struktuře a pro predikci únavové životnosti. Ve dvou kritických místech jsou zaznamenávány hodnoty napětí a přetvoření představující jednotlivé fáze cyklického zatěžování. Tyto hodnoty jsou použity pro predikci únavové životnosti.
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3D print of nanocomposite photopolymer systems
Sevriugina, Veronika ; Lepcio, Petr (referee) ; Ondreáš, František (advisor)
This master’s thesis deals with the preparation of nanocomposite photopolymer systems for 3D printing. The composition and structure were studied by thermogravimetry (TGA) and scanning transmission electron microscopy (STEM). The kinetics of photoreaction with gradually increasing content of Fe3O4 and AZO particles in a commercial methacrylate resin was also characterized by the creation of Jakobs working curves, photorheology, and differential scanning photocalorimetry (photo-DSC). Subsequently, the effect of composition on the printability of materials was observed. Part of the work is also devoted to the characterization of the influence of particles on the thermomechanical properties of the resulting products using dynamic-mechanical analysis (DMA) and on the mechanical properties in pressure.
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Design of a rotary pendulum with a flexible joint
Palát, Ondřej ; Formánek, Martin (referee) ; Dobossy, Barnabás (advisor)
This Bachelor thesis is focused on design of laboratory equipment with flexible joint. It describes construction, control electronics design, microcontroller programming and mathematical modelling describing flexible joint dynamics. Model parameters were estimated based on measurements. First part also describes market survey and brief description of algorithms used for numeric parameter estimation.
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Labyrinth seals for turbines and aircraft engines
Studnička, Ondřej ; Škorpík, Jiří (referee) ; Šnajdárek, Ladislav (advisor)
This bachelor's thesis focuses on the development and optimization of labyrinth seals used in turbines with the goal of improving their efficiency and reducing energy losses. The work combines theoretical approaches with practical application. In the theoretical part, existing seals and their most advanced types were analyzed. Subsequently, several prototypes were designed and manufactured using new unconventional technologies. The issues related to production were described. Finally, the seals were experimentally measured and evaluated.
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Design of a spherical microphone array
Voch, Filip ; Schimmel, Jiří (referee) ; Liska, Matej (advisor)
Spherical microphone array is one of the ways to record spatial sound. This paper proposes rigid spherical array for beamforming and mixed order ambisonics using MEMS sensors connected with TDM bus. MEMS sensors are used due to their small size. Digital output signal is transferred to external signal processor using time division multiplexing. This paper describes an approach to design of the array for beamforming using mathematical methods for node layout on a sphere and for ambisonics using spherical harmonic functions. For prototype realization there is created design with uniformly distributed microphones on the sphere. There are flexible printed circuit boards designs for connecting the microphones. Those boards are then connected to central printed circuit board, where are the signals converted to resp. from differential signal for transfer between the array and the signal processor. RJ-45 connectors are being used for this transfer. Microphones are connected to the buses by USB-C connectors. The result is framework solution including 3D model and printed circuit board designs for microphone connection. 3D model is designed in Fusion 360 software and printed circuit boards in KiCad.
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Demonstration kit for fiber optic sensing system
Beránek, Karel ; Klíčník, Ondřej (referee) ; Dejdar, Petr (advisor)
This bachelor thesis focuses on the design and implementation of a~demonstration kit for a~fiber optic sensing system. The thesis includes a~theoretical analysis of optical phenomena such as polarization, dispersion, and interference, which are crucial to understanding the principles of fiber optic sensors. The designed sensing system comprises a~Mach-Zehnder interferometer, a~UP-Board development kit, an external 24-bit sound card, and a~touch display. The practical part of the thesis is focused on the construction of the enclosure using 3D printing, the integration of individual components, the design of a~custom application, and the testing of the system. The results of this work contribute to the development of knowledge in the field of fiber optic sensors and can be utilized in both academic and industrial settings.
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System for Support of Short-Term Car Rentals Based on Carsharing
Vrtal, Petr ; Bidlo, Michal (referee) ; Šimek, Václav (advisor)
The aim of this thesis is to create a system for the transformation of an ordinary passenger car into a vehicle capable of sharing in the form of short-term loans. Vehicle rentals are completely unattended, which was achieved by implementing service applications in the form of an administration and user tool. The administrative application was created using web technologies, primarily Next.js and React. The customer application was implemented with the goal of high portability, and therefore its development was directed to mobile platforms using the React Native framework and the Expo tool. The vehicle is equipped with its own designed IoT end device in the form of a printed circuit board, capable of permanent wireless connection to the network based on LTE-M technology and MQTT protocol. The purpose of this device is to provide current vehicle data obtained by reading communication on the CAN bus, connecting to a standard OBD-II diagnostic port. An important part of the work was the execution of a series of tests of all sub-aspects of the implemented architecture, focusing mainly on reliability, resulting functionality and user-friendliness. The resulting system was tested in real operation and represents a way of non-invasively transforming a regular passenger car into a car capable of sharing.
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Design of nozzle for ozone admission
Krajcar, Ivo ; Hudec, Martin (referee) ; Rudolf, Pavel (advisor)
The thesis consists of three main parts. The first part contains a research focused on cavitation and fractal geometry. Furthermore it researches disinfection, mainly disinfection using UV radiation and ozone. It is concluded by mentioning advanced oxidising processes used for dangerous pollutant elimination and pointing out of positives and negatives of the individual technologies. The main goal of the fractal geometry research was to briefly explain what a fractal is and how to create different types and degrees of fractals. The second part of the thesis contains a simplified description of the design of a fractal orifice with air suction. This orifice is compared to a simple orifice with a circular opening in the last part of the thesis. Both orifices have the same cross section flow area. This part also describes a simple UV reactor design process. The third part of the thesis describes the experimental measurements of both of the orifices. The data gained from the measurements show that the fractal orifice has a better mixing influence than the circular one and also that the fractal orifice has a wider operational range than the circular one.
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Design of Rubik's Cube Solver
Palán, Petr ; Šperka, Petr (referee) ; Svoboda, Petr (advisor)
The Rubik’s Cube is one of the most famous puzzles in the world, it has evolved into countless variations and in its solving is competed all over the world. However, the record time for its solution is no longer held by a human, but by a robot. This bachelor thesis deals with the structural design and subsequent implementation of the mechanical part of the solver for the Rubik's Cube. A research of existing solvers is carried out and then individual conceptual designs are proposed. The chosen variant is then elaborated in the structural design. It individually controls 5 walls of the cube and thus ensures the possibility of its solving without the need for further positioning and at the same time there is space for comfortable insertion of the cube. The design is then realised by 3D printing. Thereafter an electronic part is connected to the created structure and a simple program written to test the structure is executed using a microcomputer. The result of the testing is that the design is functional but there is room for improvement.
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