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Stability problems study of framed structures
Piják, Jiří ; Vlk, Zbyněk (referee) ; Zídek, Rostislav (advisor)
In the first chapter the problem of ideal member, member with initial curvature and meaning of Euler’s critical force is regarded. Parameters of stability, mainly calculation of critical loading and buckling lengths, are studied in the second part. The same part contains comparison of results of computational programs and mechanical approach. Next attention is paid to imperfections, to possibilities of determination and comparison of results on a simple member. Comparison of possible judgements of buckling on a simple beam and on frames according to ČSN EN 1993-1-1 is performed on the final part.
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Roof of the swimming pool
Pelikán, Adam ; Šopík, Leonard (referee) ; Stráský, Jiří (advisor)
This diploma thesis is about designing the structure of roof of swimming stadium. Three solutions are created - concrete arc with tie, steel truss slab and concrete pretensioned membrane. One choosed solution - concrete pretensioned membrane - is afterwards developed. In the beginning there are several designs of geometry fulfilling the requirements for given type of structure being created. In part of static calculation, the parametrical mathematical model in form of macro in APDL language for Ansys software has been created. Afterwards all the parameters (initial state of cables, level of pretension, dimensions of membrane and peripheral frame, etc.) has been optimized in order to the membrane be fulfilling criterias for ultimate limit state and serviceability limit state. Afterwards other selected parts of structure has been checked. On basis of designed geometry and design checks in static calculation the drawings of conctruction and designed parts has been created. In the end, the 3D model of the structure has been created in graphical software Rhinoceros. Then visualizations of structure in concstruction stages and after completion has been rendered.
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Pedestrian bridges formed by a flat arch
Jurík, Michal ; Stráský, Jiří (advisor)
This doctoral thesis focuses on the research of the pedestrian bridges formed by the flat arch. To understand the basic static behaviour of the flat arch it was necessary to make a study of the development of the direct flat arch as footbridge with large span and the impact of stiffness on its camber. For the mathematical modeling FEM software ANSYS were used. The calculation has shown that a design of purely concrete flat arch would demand enormous bending stiffness, which can be achieved only through a massive cross-section. The findings gained in this chapter were further used to design a unique pedestrian bridge formed by the curved in plan flat arch, where to transfer of the large bending moments a steel pipe was designed. Several variants with different span and rise of the arch in plan were tested. From the tested variants was then selected footbridge with a span of 45 m and with the rise of the arch 10 m, which seemed to be the best solution according to the calculations and it was further analyzed in detail. The studied structure is formed by curved concrete slab that is stiffened through the steel brackets on the inner side of a steel tube with a graded thickness. The external cables that are situated in the handrail pipe balance the dead load torsional moment. Designed structure and the static analysis procedure were verified on a fully functional 1:6 scale model. The thesis describes the model analogy used for the design of the model, its structural design and its implementation. Load tests on the model confirmed correctness of the design of the proposed curved in plan pedestrian bridge, its high carrying capacity and the accuracy of the developed procedure of static analysis. Results and experiences acquired from the design and the realization of model are the basis for a practical realization of studied structures. The last part of the thesis deals with the possibility of replacement of the steel components with concrete in pedestrian bridges formed
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Pedestrian bridges formed by a flat arch
Jurík, Michal ; Stráský, Jiří (advisor)
This doctoral thesis focuses on the research of the pedestrian bridges formed by the flat arch. To understand the basic static behaviour of the flat arch it was necessary to make a study of the development of the direct flat arch as footbridge with large span and the impact of stiffness on its camber. For the mathematical modeling FEM software ANSYS were used. The calculation has shown that a design of purely concrete flat arch would demand enormous bending stiffness, which can be achieved only through a massive cross-section. The findings gained in this chapter were further used to design a unique pedestrian bridge formed by the curved in plan flat arch, where to transfer of the large bending moments a steel pipe was designed. Several variants with different span and rise of the arch in plan were tested. From the tested variants was then selected footbridge with a span of 45 m and with the rise of the arch 10 m, which seemed to be the best solution according to the calculations and it was further analyzed in detail. The studied structure is formed by curved concrete slab that is stiffened through the steel brackets on the inner side of a steel tube with a graded thickness. The external cables that are situated in the handrail pipe balance the dead load torsional moment. Designed structure and the static analysis procedure were verified on a fully functional 1:6 scale model. The thesis describes the model analogy used for the design of the model, its structural design and its implementation. Load tests on the model confirmed correctness of the design of the proposed curved in plan pedestrian bridge, its high carrying capacity and the accuracy of the developed procedure of static analysis. Results and experiences acquired from the design and the realization of model are the basis for a practical realization of studied structures. The last part of the thesis deals with the possibility of replacement of the steel components with concrete in pedestrian bridges formed
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Roof of the swimming pool
Pelikán, Adam ; Šopík, Leonard (referee) ; Stráský, Jiří (advisor)
This diploma thesis is about designing the structure of roof of swimming stadium. Three solutions are created - concrete arc with tie, steel truss slab and concrete pretensioned membrane. One choosed solution - concrete pretensioned membrane - is afterwards developed. In the beginning there are several designs of geometry fulfilling the requirements for given type of structure being created. In part of static calculation, the parametrical mathematical model in form of macro in APDL language for Ansys software has been created. Afterwards all the parameters (initial state of cables, level of pretension, dimensions of membrane and peripheral frame, etc.) has been optimized in order to the membrane be fulfilling criterias for ultimate limit state and serviceability limit state. Afterwards other selected parts of structure has been checked. On basis of designed geometry and design checks in static calculation the drawings of conctruction and designed parts has been created. In the end, the 3D model of the structure has been created in graphical software Rhinoceros. Then visualizations of structure in concstruction stages and after completion has been rendered.
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Stability problems study of framed structures
Piják, Jiří ; Vlk, Zbyněk (referee) ; Zídek, Rostislav (advisor)
In the first chapter the problem of ideal member, member with initial curvature and meaning of Euler’s critical force is regarded. Parameters of stability, mainly calculation of critical loading and buckling lengths, are studied in the second part. The same part contains comparison of results of computational programs and mechanical approach. Next attention is paid to imperfections, to possibilities of determination and comparison of results on a simple member. Comparison of possible judgements of buckling on a simple beam and on frames according to ČSN EN 1993-1-1 is performed on the final part.
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