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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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Trends in the design and creation of new materials
Kašičková, Václava ; Gaff, Milan (advisor) ; Babiak, Marian (referee)
Thesis investigates the flexural properties of modified laminated wood. Thesis examined two wood species - beech and aspen. The aim was to describe effect of wood species, material thickness, densification, adhesives and loaded cyclic stress on selection of mechanical properties.
Wood species and thickness of material were determined as factors with very significant impact. They affected modulus of elasticity, limit of proportionality and bending strength. All these characteristics achieved higher values while testing beech lamellas. Degree of densification does not appear as a very significant factor. Comparing modulus of elasticity in this thesis and data given in the literature it is possible to say that densified lamellas used in this research reached higher values.
This thesis also investigates tensile-shear strength and bendability.
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Brickmaking grogs and their thermo-dilatometric determination
Hladík, Václav ; Skotal, Zbyněk (referee) ; Sokolář, Radomír (advisor)
Main focus of the bachelor´s thesis is use of rock waste fraction as an alternative raw material to traditional quartz sand. Effect of this substitution on ceramic produts properties is outlined. Key properties are water absorption, flexural strength and compressive strength. The practical part traces the potential of alternative grogs. Their behavior is monitored by DKTA analysis, water absorption tests and strength tests. Thesis includes author´s suggestion of an optimal grog based on publications and results of the practical part.
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Hybrid dental composites combining short fibers and particulate fillers
Klieštiková, Nikola ; Přikryl, Radek (referee) ; Bystřický, Zdeněk (advisor)
This work deals with the hybrid composite material combining particulate filler with short fibers for dental applications. The barium micro-filler and the short glass fibers were treated with -methacryloxypropyltrimethoxysilane in cyclohexane using n-propylamine. The barium micro-filler and the short glass fibers were mixed with the matrix based on a dimethacrylate resin. The effects of the addition of short glass fibers on mechanical properties were studied. Surface treatment of the filler was characterized by thermogravimetric analysis (TGA) and diffuse reflectance infrared fourier transform spectroscopy (DRIFTS). Fracture surfaces and the adhesion to the matrix was observed by scanning electron microscope (SEM). The modulus of elasticity and strenght was determined by three point bending flexural test. Critical values of the stress intensity factor annd energy release rate were determined using the three point bending flexural test of notched specimens. The particulate filler increased the flexural modulus of elasticity and fragility. The addition of short fibers had little effect on flexural modulus of elasticity, but increased the flexural strength and fracture toughness of the specimen.
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The influence of coatings on fracture behaviour of ledeburitic steel
Šafář, Martin ; Jurči,, Peter (referee) ; Hadraba, Hynek (advisor)
This work deals with tool steel Vanadis 6. It describes the preparation of samples for the three-point bending test, with which it examines the influence of surface roughness, the effect of nitriding, coating and duplex coatings on fracture behaviour of the steel. First, it examines bending strength and the total energy required to work of fracture. The work also includes mapping and measurement of surface roughness on different layers. This measurement is performed on a confocal microscope.
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