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Design proposal and modal analysis of fixture for CubeSat vibration tests
Pospíšil, Jakub ; Bartoněk, Jaroslav (referee) ; Lazar, Václav (advisor)
Hnutí CubeSatů se v současné době těší vzrůstající oblibě, především díky možnosti zapojení širšího okruhu institucí do vesmírného výzkumu. Tento zájem zároveň vyvolává nutnost provádět mechanické zkoušky CubeSatů dříve, než je bude možné vypustit do vesmíru. Tato závěrečná práce zpracovává problematiku mechanických zkoušek u CubeSatů a provádění jejich vibračních zkoušek. Na základě této rešerše je proveden návrh přípravku o velikosti 6U včetně modální analýzy a ověření vyrobitelnosti.
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Structural-mechanical characteristics of the selected type of low-carbon steel after cold drawing and heat treatment
Stopka, Maroš ; Molliková, Eva (referee) ; Pacal, Bohumil (advisor)
This bachelor's thesis focuses on changes in the mechanical properties of low-carbon wire that has been cold-drawn and subsequently heat-treated. Mechanical tests, from which the values of elongation, yield strength and tensile strength were measured, were performed on all samples within 24 hours after they were collected. Two different production rates were established on the hot dip galvanizing line to achieve different time intervals of the annealing process. The experiment was performed at all stages of wire diameter reduction, including the input material. This work also includes metallographic analyzes of samples that have been both polished and etched. The most representative samples were selected for analysis. The results show that deformation caused changes in mechanical properties and an increase in strain hardening, which was subsequently removed by heat treatment.
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Assessment of the use of 3D printing technology in industry
Blecha, Miroslav ; Šafl, Pavel (referee) ; Binar, Tomáš (advisor)
This bachelor's thesis deals with the issue of 3D printing of polymer materials. The aim of the theoretical part is to describe the history, basic technologies and materials of 3D printing. Attention was also paid to various climatic influences related to the degradation of polymers. The experimental part deals with the mechanical testing of test specimens printed from two selected materials, one of which is further chosen for loading in the climatic chamber. An electron microscope was also used during the research in order to observe fracture surfaces. The results from the mechanical tests of hardness, toughness and tensile strength were evaluated and based on them a case study was then developed regarding the IVECO 4x4 MRV vehicle.
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Factors influencing results of laboratory tests of mechanical properties of rocks
Čermák, Martin ; Přikryl, Richard (advisor) ; Drozd, Karel (referee)
This submitted bachelor thesis deals with the influence of different factors that may influence the results of mechanical tests of rock. This is a search thesis, which draws primarily from academic articles and conference papers. In the introduction this thesis describes the laboratory testing methods, which we can test a rocks and obtain a strength characteristics and additionally the thesis describes the strain and deformational properties of rocks. In the second part of this thesis there are defined a factors that influence the results of mechanical tests, namely those given by their composition and structure of the tested rocks and on its physical properties. Additionally there are also included factors that can be influenced, such as test conditions and preparation of test specimens. For each selected factor there is a description of how it affects the results of mechanical tests of the different lithological types of rocks. This thesis brings clear knowledge, that the described factors can have strong effects on mechanical properties and is beneficial to these factors account for the mechanical tests.
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Marginal conditions and their influence in the production of reinforced steel fibres in concrete
Loyková, Markéta ; Řiháček, Jan (referee) ; Císařová, Michaela (advisor)
Constantly increasing demands of customers for the speed of realization of the construction and reduction of all input costs have been reflected in civil engineering by high demand for reinforced steel fibers in concrete. The steel reinforcement has significant role in this composite material. This means that reinforcement (wires) provide the required physicochemical properties to the concrete. It is necessary to pay attention also to the marginal conditions and their influences in the production of wire. In close cooperation with the companies Krampe Harex CZ and Cemex Czech Republic, an analysis of the conditions of the drawing process and subsequent influence of dispersed steel reinforcement on the final product was created. The economic aspects of the production of dispersed steel reinforcement in concrete were also mentioned.
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Factors influencing results of laboratory tests of mechanical properties of rocks
Čermák, Martin ; Drozd, Karel (referee) ; Přikryl, Richard (advisor)
This submitted bachelor thesis deals with the influence of different factors that may influence the results of mechanical tests of rock. This is a search thesis, which draws primarily from academic articles and conference papers. In the introduction this thesis describes the laboratory testing methods, which we can test a rocks and obtain a strength characteristics and additionally the thesis describes the strain and deformational properties of rocks. In the second part of this thesis there are defined a factors that influence the results of mechanical tests, namely those given by their composition and structure of the tested rocks and on its physical properties. Additionally there are also included factors that can be influenced, such as test conditions and preparation of test specimens. For each selected factor there is a description of how it affects the results of mechanical tests of the different lithological types of rocks. This thesis brings clear knowledge, that the described factors can have strong effects on mechanical properties and is beneficial to these factors account for the mechanical tests.
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Seismic test of the switching devices on the low voltage
Dubský, Martin ; Mikyska, Kamil (referee) ; Dostál, Lukáš (advisor)
This work analyzes the seismic tests to valid technical starnards. Here is explained the term technical standard and written summary requirements for seismic resistance circuit breakers low voltage. The work includes devices suitable for the purpose and extreme laboratories dealing with seismic tests. The final section provides a draft test station with estimated economic return. Seismic tests are a very important part in the design of not only switching technology. It allows you to simulate the selected mechanical effects which may on the unit during operation or transportation to work and increase its reliability.
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