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Mechanical response of glass fiber-reinforced polymer composite
Širjovová, Veronika ; Svěrák, Tomáš (referee) ; Čech, Vladimír (advisor)
The bachelor thesis is concerned with mechanical properties of glass fiber-reinforced polymer composites depending on the surface modification of fibers and the volume fraction of fibers in the composite. The tested samples in a form of composite beams were consisted of polyester matrix reinforced with long glass fibers without surface treatment (unsized) and with commercial sizing. Shear and flexural tests were employed to evaluate adhesion at the fiber-matrix interface. The theoretical part focuses on literary search for composites, their components (matrix, reinforcement, interphase) and methods of testing their mechanical properties. The experimental part describes used materials, procedures and methods. In the result part, an assessment of the influence of the given conditions on the shear and flexural strength of the composite is summarized.
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Mat roll cutter
Šrámek, Michal ; Holub, Michal (referee) ; Foller, Bronislav (advisor)
The diploma thesis deals with the construction of a textile machine. More specifically, it deals with the construction of a vertical cutter of non-vowen fabrics that are made of polymerous fibres or fibre glass. The surface density of the material used ranges from 100 – 500 g/m2, the width of a role is 2000 mm and the weight is 150 kg. The machine is supposed to be designed in such a way so that the mat roles could be cut in any point.
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Properties of pultruded composites based on epoxy matrix
Huljak, Pavel ; Bálková, Radka (referee) ; Přikryl, Radek (advisor)
The theoretical part of this bachelor thesis deals with research of composite materials, especially based on polymer epoxy and polyester resins, using as reinforcement a glass fiber bundles. The practical section includes the production of composite materials and their components along with the most important testing methods. The main goal of the experimental part is to characterize the optimal conditions pultrusion production of epoxy composite material. Another point is characterization of mechanical and chemical properties of the produced composite at a number of test methods. Finally the optimized epoxy composite materials are compared with composites based on polyester resins.
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Mechanical response of long-fiber-reinforced polymer composite
Škriniarová, Nina ; Prokeš, Jan (referee) ; Čech, Vladimír (advisor)
This diploma thesis is focused on monitoring of mechanical response of long-fiber reinforced polymer composite. Main part of this thesis was preparation of long-fiber reinforced composite specimens, on which matrix was reinforced by commercially sized glass fibers. For comparison of properties were prepared specimens reinforced by unsized glass fibers. Apart from preparing specimens reinforced by long glass fibers were prepared specimens contains long carbon fibers. For evaluation of mechanical response of the prepared composite specimen were used flexural test and short beam shear test. Mechanical response was evaluated with universal testing machine ZWICK Z010 and data were processed in OriginPro 8 program. Thanks to evaluation of the mechanical response of the prepared specimens was assessed adhesion to fiber-matrix interface. By examining the mechanical response or adhesion can be assessed efficiency of commercial fiber surface treatment and so standardize measurement to compare other options of surface treatments.
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Bound mixtures for the base layers of pavements using glass fibers
Elabd, Ahmed Samy ; Šperka, Pavel (referee) ; Stehlík, Dušan (advisor)
This thesis consists of a theoretical and a practical part. The theoretical part gathers available information on bound mixtures for base layers of pavements, providing basic information on the most commonly used types of recycled materials and their use in roads. It also includes various types of binders and requirements for their use. The thesis also explains the importance of reducing the amount of dosed hydraulic binders to eliminate negative impacts on the environment and for economic reasons, offering an alternative possibility of stabilizing soils into mixtures for subbase layers of roads. The practical part of this thesis focuses on the possibility of using glass fibers as a reinforcing element at low doses of binder. The main goal was to evaluate the designed mixtures with a hydraulic binder with the addition of glass fibers, depending on the results of bound mixtures with only glass fiber addition. These options were verified and subsequently compared using laboratory tests.
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Mineral wool and binding agent interaction and behavior study
Fiala, Michal ; Šoukal, František (referee) ; Ptáček, Petr (advisor)
Diploma's thesis describes resolution of cause technological problems in mineral wool manufacturig in company Saint-Gobain Orsil. Main attention is paid to thermal and volatile process in mineral wool from filtration chamber and common commercial sales. Samples of mineral wool were characterizated by thermal analysis (simultaneous TG-DTA), effluent gas analysis (EGA), infrared spectroscopy (FT-IR), electron microscopy (SEM) and X-ray diffraction (XRD). Thermal analysis experiments was used to check thermal volatile processes. Technological problem of burning is linked with rise of isocyanic acid.
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Plasma surface modification of glass fibers and its optimization
Širjovová, Veronika ; Knob, Antonín (referee) ; Čech, Vladimír (advisor)
Diploma thesis deals with glass fiber surface modification using plasma-enhanced chemical vapor deposition in order to prepare functional interface that enhances the properties of polymer composites. The effect of deposition conditions on shear strength was observed with respect to the chemical composition of the deposited film. Thin films were deposited on planar substrates and fibers using monomer tetravinylsilane in a mixture with oxygen at selected power of plasma discharge. Chemical composition of prepared material was analyzed by infrared spectroscopy. Planar substrate film adhesion was measured using the scratch test. The composite sample was prepared by embedding the surface modified fibers in unsaturated polyester resin, followed by the curing process. The cured composite sample underwent the short beam shear test.
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Mechanical properties of glass fibers
Ševnina, Marija Vladimirovna ; Svěrák, Tomáš (referee) ; Čech, Vladimír (advisor)
The bachelor thesis deals with the examination of mechanical properties of unsized glass fibers and commercially sized glass fibers. The main objective is to determine the tensile strength, modulus of elasticity, and ductility for the fibers depending on the surface modification. To determine these properties, fiber diameters were measured using an Olympus BX 50 optical microscope followed by a tensile test on the Universal Testing Machine, ZWICK / Z010 / TH2A.
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FRP for concrete reinforcement
Blahová, Aneta ; Vaněrek, Jan (referee) ; Bodnárová, Lenka (advisor)
The bachelor thesis deals with composite polymer FRP reinforcement. It descibes the method of manufacturing FRP reinforcements, which are their properties and what materials are used by manufacturers. Lists FRP reinforcement application in various structures. Also mentions the durability of FRP reinforcement in an aggressive environment and the cohesiveness of FRP reinforcement with concrete. The conclusion of the work is a proposal for experimental testing of a bond between FRP reinforcement and concrete.
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