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Numerical modeling of behavior of a particle composite with crosslinked polymer matrix
Máša, Bohuslav ; Ševčík, Martin (referee) ; Náhlík, Luboš (advisor)
The master's thesis deals with the determination of macroscopic behavior of a particulate composite with cross-linked polymer matrix under tensile load. The main focus of thesis is estimation of mechanical properties of a composite loaded by tensile loading using numerical methods (especially finite elements method). Investigated composite is composed of matrix in a rubbery state filled by alumina-based particles (Al2O3). Hyperelastic properties of the matrix have been modeled by the Mooney-Rivlin material model. Different compositions of particles, their different shape, orientation and different volume fractions have been considered. For all these characteristics of composite numerical models have been developed. The damage mechanisms of the matrix have also been taken into account. Results of numerical analyses have been compared with experimental data and good agreement between numerical models with damage mechanisms of matrix and experimental data has been found.
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Application of functional fillers in composites: Effects of fillers content on the mechanical properties
Krhut, Jiří ; Petruš, Josef (referee) ; Poláček, Petr (advisor)
This work deals with the application of selected types of fillers and monitoring their addition to the specific properties of the resulting composite material. The theoretical part of this work includes a general description of composite materials, and selected types of matrices, followed by a brief description of the characteristics of particulate composites and the effect of fillers on selected material properties. In the experimental part, samples of polyester resin were prepared to contain the given content of filler based on aluminium hydroxide (Al(OH)3), expanded glass, hollow glass microspheres, and fillers based on nitrogen and phosphorus compounds. Subsequently, the influence of the used fillers on the rheological properties, flammability of the material, on mechanical and thermomechanical properties was monitored. Flame test methods, bending test methods and dynamic mechanical analysis (DMA) were used to evaluate the samples. Finally, the measurement was supplemented by an analysis of fracture surfaces using a scanning electron microscope (SEM). The addition of additives improved the fire resistance of the prepared materials. The mechanical and thermomechanical properties of the prepared materials differed significantly depending on the applied fillers and their content.
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Particle Polymer Composite in structural details of the building envelope
Dostálová, Darina ; Lavický, Miloš (referee) ; Vokoun,, David (referee) ; Matějka, Libor (advisor)
Due to a European energy concept for reducing energy consumption and also the concept of sustainable development, there is a growing demand for reduced energy consumption during the operation of the building and hence increasing demands on the thermal and mechanical properties of the building envelope. For this reason, it is necessary to look for materials that could meet both thermal and mechanical properties, as well as mechanical resistance and loadability, especially for the application for the foundations of the house, the base of the house and for application to structural details for elimination of the thermal bridges between interior and exterior boundaries. The main motivation for choosing the topic of thesis was to find materials derived from recycled or secondary raw materials that would be suitable for manufacturing composite applicable for structural details in the envelope of the building and for insulating in humid environment. An economic and environmental aspect plays an important role in the choice of material. The main theme of the thesis is the laboratory manufacturing of a composite with a thermoplastic matrix derived from recycled plastic materials and waste foam as a phase. Has been developed a unique Waste-based Particle Polymer Composite (WPPC) made from recycled foam and polypropylene. However, before WPPC can be reliably used by construction designers, physical properties of WPPC must be accurately identified. Therefore, it was designed laboratory manufacturing system and sample testing system, it was studied thermal, mechanical, thermomechanical and moisture absorptivity of WPPC. Application of finished composite material with satisfying thermal insulation properties to structural details to eliminate the thermal bridge, was the next step. These are details of the unloaded, prefabricated balconies, windows, atics, as well as basement constructions and the heel of the central load-bearing wall, the terrain flooring and the staircase wall
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Composite materials with enhanced coefficient of linear attenuation of ionizing radiation
Novotný, Kamil ; Petruš, Josef (referee) ; Kučera, František (advisor)
Ionizing radiation has many useful applications in the fields of healthcare, food industry, nuclear energy and others but poses a hazard to human health in higher doses. In this work, composite materials with enhanced ionizing radiation attenuation properties were prepared. Unsaturated polyester resin was reinforced with inorganic fillers containing elements such as bismuth or barium. Morphology of the samples was studied using scanning electron microscopy. Theoretical values of mass attenuation coefficients were obtained for photon energies 662 keV and 1253 keV using the XCOM software. The attenuation of ionizing gamma radiation was experimentally measured using radioactive sources 137Cs and 60Co. Linear attenuation coefficients and half value layers of the materials were determined using the obtained data. Addition of the fillers improved the shielding properties of the matrix. Composite containing bismuth oxide achieved the highest values of linear and mass attenuation coefficients. The experimental results were found to be in good agreement with theoretical values. Moreover, influence of the fillers on impact toughness has been evaluated.
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Application of functional fillers in composites: Effects of fillers content on the mechanical properties
Krhut, Jiří ; Petruš, Josef (referee) ; Poláček, Petr (advisor)
This work deals with the application of selected types of fillers and monitoring their addition to the specific properties of the resulting composite material. The theoretical part of this work includes a general description of composite materials, and selected types of matrices, followed by a brief description of the characteristics of particulate composites and the effect of fillers on selected material properties. In the experimental part, samples of polyester resin were prepared to contain the given content of filler based on aluminium hydroxide (Al(OH)3), expanded glass, hollow glass microspheres, and fillers based on nitrogen and phosphorus compounds. Subsequently, the influence of the used fillers on the rheological properties, flammability of the material, on mechanical and thermomechanical properties was monitored. Flame test methods, bending test methods and dynamic mechanical analysis (DMA) were used to evaluate the samples. Finally, the measurement was supplemented by an analysis of fracture surfaces using a scanning electron microscope (SEM). The addition of additives improved the fire resistance of the prepared materials. The mechanical and thermomechanical properties of the prepared materials differed significantly depending on the applied fillers and their content.
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Particle Polymer Composite in structural details of the building envelope
Dostálová, Darina ; Lavický, Miloš (referee) ; Vokoun,, David (referee) ; Matějka, Libor (advisor)
Due to a European energy concept for reducing energy consumption and also the concept of sustainable development, there is a growing demand for reduced energy consumption during the operation of the building and hence increasing demands on the thermal and mechanical properties of the building envelope. For this reason, it is necessary to look for materials that could meet both thermal and mechanical properties, as well as mechanical resistance and loadability, especially for the application for the foundations of the house, the base of the house and for application to structural details for elimination of the thermal bridges between interior and exterior boundaries. The main motivation for choosing the topic of thesis was to find materials derived from recycled or secondary raw materials that would be suitable for manufacturing composite applicable for structural details in the envelope of the building and for insulating in humid environment. An economic and environmental aspect plays an important role in the choice of material. The main theme of the thesis is the laboratory manufacturing of a composite with a thermoplastic matrix derived from recycled plastic materials and waste foam as a phase. Has been developed a unique Waste-based Particle Polymer Composite (WPPC) made from recycled foam and polypropylene. However, before WPPC can be reliably used by construction designers, physical properties of WPPC must be accurately identified. Therefore, it was designed laboratory manufacturing system and sample testing system, it was studied thermal, mechanical, thermomechanical and moisture absorptivity of WPPC. Application of finished composite material with satisfying thermal insulation properties to structural details to eliminate the thermal bridge, was the next step. These are details of the unloaded, prefabricated balconies, windows, atics, as well as basement constructions and the heel of the central load-bearing wall, the terrain flooring and the staircase wall
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Numerical modeling of behavior of a particle composite with crosslinked polymer matrix
Máša, Bohuslav ; Ševčík, Martin (referee) ; Náhlík, Luboš (advisor)
The master's thesis deals with the determination of macroscopic behavior of a particulate composite with cross-linked polymer matrix under tensile load. The main focus of thesis is estimation of mechanical properties of a composite loaded by tensile loading using numerical methods (especially finite elements method). Investigated composite is composed of matrix in a rubbery state filled by alumina-based particles (Al2O3). Hyperelastic properties of the matrix have been modeled by the Mooney-Rivlin material model. Different compositions of particles, their different shape, orientation and different volume fractions have been considered. For all these characteristics of composite numerical models have been developed. The damage mechanisms of the matrix have also been taken into account. Results of numerical analyses have been compared with experimental data and good agreement between numerical models with damage mechanisms of matrix and experimental data has been found.
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