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Additional reinforcement of wood elements
Janoušek, Radek ; Vejpustek,, Zdeněk (referee) ; Vaněrek, Jan (advisor)
This diploma thesis deals with the possibilities of additional reinforcement of wooden elements using different types of BFRP materials. In the practical part, an experiment of reinforcing plywood with external reinforcement using BFRP fabrics with different basis weights was performed. As part of the strength tests performed, the specimens were subjected to bending and shear stresses. To verify the bonding quality of the plywood, the bodies were exposed to the effect of elevated temperature and a delamination test was performed to determine the bonding quality of the plywood joints. The achieved values were evaluated and compared with the available literature.
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Influence of zinc on mechanical properties of cement composites
Štarha, Tomáš ; Šilerová,, Iva (referee) ; Šiler, Pavel (advisor)
The theme of this bachelor thesis is to monitor the effect of zinc on mechanical properties of portland cement. Zinc was tested in the form of zinc oxide. Three acceleration additives were added, calcium oxide, formic acid and calcium formate in various proportions. Furthermore, the mechanical properties of all these mixtures were monitored by measuring flexural strength and compressive strength at 7 and 28 days after mixing and mixtures were analyzed by XRD and DTA. Also using isoperibolic calorimetry, the hydration of CEM 42.5 R cement zinc oxide was monitored.
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Stavba a vybrané vlastnosti dřeva paulownie
Přikryl, Vojtěch
This bachelor thesis deals with the structure and selected properties of wood paulownie. Test sample sets were manufactured from purchased joint boards tests were conducted to determine the following characteristics wood paulownie. The mechanical properties of the wood compressive strength 26.52 MPa and bend strength 39.70 MPa. From the physical the properties of wood were measured density at humidity 0 % 263.39 kg·m−3 and swelling in radial direction 2.78 %, in tangential directions 4.92 % and volumetric 8.75 %. Finaly and natural durability of wood was evaluated. The first part is described the theory of mechanical and physical properties of wood, in the second part the procedure for evaluating the measured values and the results compared with the first is described theoretical part.
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Možnosti nastavování překližek do větších formátů
Lempera, Martin
The bachelor´s work deals with problematics of longitudinal setting of plywood materials, for a purpose of comparing of mechanical features of particular glue mixtures at the connecting at chamfer. The first part of the work deals with characteristics, production and division of plywood boards. Follows the information about connecting and surface finish of plywood boards. The second part of the work contains methodology of carrying out tests and results of particular groups of samples according to glued materials. The main testing of samples was focused on modulus of rupture (MOR) and modulus of elasticity (MOE). Further performed tests were for a purpose of finding out of: moisture, density, durability of edges, their dampness and resistance of surfaces of plywood boards against abrasion.
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Vliv působení vnějšího prostředí na základní vlastnosti materiálu pro výrobu exteriérových dílců nábytku
Križanová, Adéla
The diploma thesis deals with the impact of the external environment on the basic properties of composite material Richlite and its suitability for exterior furniture manufacturing. There is a brief overview of the properties of Richlite, possible ways of utilization and production process of the material itself and individual components. The main goal of the diploma thesis is to determine the influence of temperature changes and exposure to elevated temperatures on the mechanical properties of the material. The observed properties are the modulus of elasticity and the flexural strength ascertained by loading in a three-point system. The measured results were statistically evaluated, and it was found that the temperature changes could affect the flexural strength of Richlite.
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Využití alternativních výztužných materiálů ve vrstvených lepených materiálech
Svatoň, Kryštof
Thesis deals with possibilities of reinforcement of plywood boards with natural materials in order to improve mechanical and physical properties. 5-layer spruce boards were reinforced under top layer with basalt fabric and jute. There was used environmental friendly glue for plywood fabrication. Results indicate increase in mechanical properties of boards with basalt fabric reinforcement. Mechanical properties of boards reinforced by jute were decreased.
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Vliv hydrotermické úpravy na vybrané vlastnosti lisovaného dřeva
Jacko, Ondřej
This bachelor thesis deals with the influence of hydrothermal treatment on selected properties of compressed wood of plantation poplar and larch. There were examined the properties of wood which was hydrothermally modified in a saturated steam environment at 90 ° C. Dimensional stability, density and bending strength were among the properties studied. Dimensional stability was investigated in 4th cycles of soaking in water and subsequent drying. The dimensional stability was guaranteed for compressed specimens that had been steamed for 10 days. By boiling wood in water in the 4th cycle it has been shown that larch is more dimensionally stable.
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Study of thermal resistance of reinforced wood members
Janoušek, Radek ; Krbila, Jaromír (referee) ; Vaněrek, Jan (advisor)
This bachelor's thesis studies the problem of thermal resistance of a system consisting of timber as a structural member with external strengthening in the form of carbon fibre reinforced polymer lamellas connected by various types of adhesives. Attention will be paid to the thermal resistance of reinforced timber members with subsequent mechanical load.
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Preparation and Characterization of Porous Magnesium Based Materials
Březina, Matěj ; Pacal, Bohumil (referee) ; Vojtěch, Dalibor (referee) ; Ptáček, Petr (advisor)
Bulk magnesium materials produced nowadays via powder metallurgy are based on a vastly extensive technological spectrum, which makes it possible to create a wide range of materials. This work focuses on the preparation of bulk materials from magnesium powder by cold pressing and hot pressing, sintering and field assisted sintering. The bulk materials were prepared in a series of compacting pressures from 100 MPa to 500 MPa and the sintering temperatures were selected in the range of 300 ° C to 600 ° C in order to characterize the influence of the manufacturing conditions and technology on the final properties of bulk materials. Prepared materials were evaluated in terms of microstructure, hardness, microhardness, three-point bend test, and fractography. From the hot pressed materials, the samples prepared at 400 and 500 MPa and 400 °C had the highest strength and hardness. The classic sintering of magnesium in the furnace with argon atmosphere proved to be ineffective due to the oxide layer on the surface and the presence of oxygen in technical argon. The SPS sintering (Spark Plasma Sintering) was the more effective with the lower applying pressure used to make the preforms and with the higher applied pressure during the SPS process itself. Highest strength and hardness were achieved in this case of materials sintered at 600 ° C prepared from free powder and the most porous preform (100 MPa). The bulk materials were prepared using all methods used, but the properties of these materials varied considerably depending on the technology used.
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Frames of Tennis Rackets
Rajdlík, Lukáš ; Němec, Karel (referee) ; Molliková, Eva (advisor)
This bachelor’s thesis deals with materials used for manufacturing of the frame of tennis rackets. The thesis informs about the frame of tennis rackets development, from the origins of tennis to these days, when there are modern technologies used. There are parts of the frame of a tennis racket and construction requirements defined. There are two samples of tennis rackets investigated and the both samples are compared with each other.
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