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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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Preparation of PP composites by grafting using monomer treated filler
Kramerová, Nina ; Žídek, Jan (referee) ; Kučera, František (advisor)
Bachelor thesis is focused on preparation of composite materials with polypropylene matrix. The composites were prepared “in situ” with using Brabender mixer. Homogenization of matrix and filler and grafting of PP with anhydride of itaconic acid treated filler proceed together according to radical mechanism of polymerization. Luperox 101 [2,5-dimethyl-2,5-di(tertbutyl-peroxy)hexane] was used as an initiator of the reaction, the concentration of the initiator was 0.5 wt %, processing temperature 210 °C, 30 rpm. PP-g-IA is a compatibilizer between the matrix and the filler. Glass fibers, calcite and two types of ground wood pulp were used as filler. Two analytical methods were chosen to analyze the efficiency of grafting, acid-base titration and infrared spectroscopy. Assigned conversion of monomer was from 42 to 87 % for various fillers.
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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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Development glass-concrete of with high mechanical properties
Plochý, Ondřej ; Lederer, Peter (referee) ; Hela, Rudolf (advisor)
This master thesis summarizes the current knowledge regarding the design and properties of glass fiber reinforced concrete products. It also deals with the design of a new concrete recipe for Dako spol. s.r.o company. There is verified effect of changes in input materials in real conditions the company to increase tensile bending strength above 20 MPa.In particular, verification of the use of building chemistry like superplasticizing additives, polymer-cement matrix or a change type or dose of glass fiber.
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The optimalization of clay building components
Melichar, Jindřich ; Šiler, Pavel (referee) ; Opravil, Tomáš (advisor)
Clay building components are nowadays one of the most used building materials in the world. Except easy availability and processability clay building components have also heat storage function. This master´s thesis will be considering possibilities of improving thermal and mechanic properties of these materils by additing suitable reinforcements.
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Influence of glass fibers as negative electrode additives on properties of the lead accumulator
Cvaniga, Tomáš ; Zimáková, Jana (referee) ; Bača, Petr (advisor)
Main topic of bachelor project is studing effects of glass fibers as additives on the properties of the negative electrode lead-acid battery for hybrid electric vehicles. Purpose of bachelor work is to examine how to increase battery life due to glass fibers. In theoretical part of work is explained the activity of both types of lead-acid batteries, battery with flooded system and battery with hermetic system. There are processed other types of batteries. There is devoted space to the chemical process that take place during the battery operation. Accumulators operate in PSoC and there are explained some possible problems during the life of battery, which can lead to lose the charging ability. In this issue there are known concepts as PLC1, PLC2 and PLC3. There are processed some graphs in practical part, that show activity in the battery DoD mode, PSoC mode and formation process. There is an aim to study how the capacity changes after PSoC I and PSoC II mode.
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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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