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Smoothed Particle Hydrodynamics in Structural Dynamics
Hušek, Martin ; Králik,, Juraj (referee) ; Maňas,, Pavel (referee) ; Kala, Jiří (advisor)
The focus of the thesis is on the application of the Smoothed Particle Hydrodynamics (SPH) method in structural dynamics with an emphasis on usage of quasi-brittle materials. The first part is focused on the introduction, history, and theoretical background of SPH. Numerical examples in which strengths and weaknesses of SPH are shown follow. In addition to pure SPH models, several coupling approaches with the Finite Element Method (FEM) are also discussed. After the introduction of SPH, the focus is on quasi-brittle materials and their reinforced variants. The numerical concept and mathematical background of the Continuous Surface Cap Model are outlined, several benchmarks are presented. Strain-rate effects and their impact on pure SPH and coupled SPH-FEM models are evaluated next. In this section, the author proposes a new approach for SPH models reinforcement with FEM beam elements. The coupling approach was named sublayer coupling and shows a potential in simulations while the SPH tensile instability is alleviated. Since concrete is often associated with heterogeneity and very specific material structure, a unique algorithm for concrete structure generation in combination with SPH is proposed in the next chapter. The concept is based on utilization of coherent noise functions which can bring a variability to numerical models. It has been proved that the algorithm is robust, stable, and easy to implement into the SPH framework. With regard to that, the so-called numerical heterogeneity, a concept of parameters variability implementation, is introduced together with examples. The last part of the thesis is dedicated to the application of SPH in real experiments. The first experiment focuses on a high velocity impact. The second experiment deals with an explosion in which the focus is on both the loaded specimen and charge. Since SPH simulates the explosive, detonation products, and the loaded specimen, it is a fully coupled fluid-structure interaction simulation.
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Graphics Demo with a Space Theme
Prajka, Martin ; Milet, Tomáš (referee) ; Herout, Adam (advisor)
This bachelor's thesis deals with the creation of graphics demo with unlimited size by using OpenGL. The thesis implements post-processing effects such as shadow mapping, bloom and gaussian blur. In addition, it describes particle system and camera animation. The demo is placed in space and it is separated into the three scenes. The end of the thesis is focused on the results of user's and performance tests.
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Sheet metal forming using liquid
Fries, Petr ; Císařová, Michaela (referee) ; Řiháček, Jan (advisor)
This work is focused on unconventional technology using liquid as forming medium. The thesis presents the principle of forming methods hydroforming and its variations, wheelon, Flexform, hydromechanical drawing and explosive forming with examples of parts produced individual methods. A comparison of their advantages and disadvantages with conventional production methods.
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Reduction of risks of explosive atmospheres in coating plants
Lužný, Jan ; Trávníček, Petr (referee) ; Kotek, Luboš (advisor)
Bachelor’s thesis deals with conditions of explosion, areas with danger of an explosion and their division into individual zones. Furthermore the thesis is focused to options for a reduction of risks of explosion and takes into account the coating plants by using primary, secondary and constructional prevention. It describes the recommendations and options for reduction of the explosion creation, eventually its results.
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Effect of volcanic ash to Air Transport
Soukop, Robin ; Šplíchal, Miroslav (referee) ; Chlebek, Jiří (advisor)
This master's thesis deals with the issue of volcanic ash as a complex and its impact on aviation, including the volcanic activity itself (conditions for its existence, for existence of eruptions and their basic products). In addition, the thesis also deals with effect of volcanic ash on aircraft and airports, possibilities of its detection or monitoring as well as mechanism of its spreading in airspace. The emphasis is laid mainly on air incidents related to volcanic ash and on danger it poses to the airspace of the Czech Republic.
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Smoothed Particle Hydrodynamics in Structural Dynamics
Hušek, Martin ; Králik,, Juraj (referee) ; Maňas,, Pavel (referee) ; Kala, Jiří (advisor)
The focus of the thesis is on the application of the Smoothed Particle Hydrodynamics (SPH) method in structural dynamics with an emphasis on usage of quasi-brittle materials. The first part is focused on the introduction, history, and theoretical background of SPH. Numerical examples in which strengths and weaknesses of SPH are shown follow. In addition to pure SPH models, several coupling approaches with the Finite Element Method (FEM) are also discussed. After the introduction of SPH, the focus is on quasi-brittle materials and their reinforced variants. The numerical concept and mathematical background of the Continuous Surface Cap Model are outlined, several benchmarks are presented. Strain-rate effects and their impact on pure SPH and coupled SPH-FEM models are evaluated next. In this section, the author proposes a new approach for SPH models reinforcement with FEM beam elements. The coupling approach was named sublayer coupling and shows a potential in simulations while the SPH tensile instability is alleviated. Since concrete is often associated with heterogeneity and very specific material structure, a unique algorithm for concrete structure generation in combination with SPH is proposed in the next chapter. The concept is based on utilization of coherent noise functions which can bring a variability to numerical models. It has been proved that the algorithm is robust, stable, and easy to implement into the SPH framework. With regard to that, the so-called numerical heterogeneity, a concept of parameters variability implementation, is introduced together with examples. The last part of the thesis is dedicated to the application of SPH in real experiments. The first experiment focuses on a high velocity impact. The second experiment deals with an explosion in which the focus is on both the loaded specimen and charge. Since SPH simulates the explosive, detonation products, and the loaded specimen, it is a fully coupled fluid-structure interaction simulation.
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Graphics Demo with a Space Theme
Prajka, Martin ; Milet, Tomáš (referee) ; Herout, Adam (advisor)
This bachelor's thesis deals with the creation of graphics demo with unlimited size by using OpenGL. The thesis implements post-processing effects such as shadow mapping, bloom and gaussian blur. In addition, it describes particle system and camera animation. The demo is placed in space and it is separated into the three scenes. The end of the thesis is focused on the results of user's and performance tests.
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Magnetic properties of the spherules from sediment in Tunguska (holocene) and North America (holocene/pleistocene)
Nábělek, Ladislav ; Kletetschka, Günther (advisor) ; Rajmon, David (referee)
In the early 20th century, 30 June 1908, the event took place, which is described as the Tunguska Event, or Tunguska. It is still not entirely clear what happened that day and the whole event was caused. The causes of events Clovis which is dated to the Younger Dryas (YD) are not entirely clear. In this period there was a sharp slowdown, which resulted in the extinction of large mammals. The link between the two events is the discovery of magnetic spherules in the sediment layer. This material may arise in several ways: fossil fuel combustion processes, ablation of cosmic material passing through the atmosphere, a large explosion in the atmosphere or atmospheric discharges (lightning). This thesis deals with analysis and Tunguska Event and Clovis event, and related research microscopic spherules (material of uncertain origin) found after the events in a layer of sediment in North America and central Siberia. The object is to compare the two events and causes of based on research and laboratory measurements of material from Clovis and Tunguska. For the analysis of magnetic spherules status was gained by the non-magnetic separation. The material was measured residual magnetization. The measurements were used magnetic scanner. On the basis of laboratory measurements of magnetic properties of spherules...
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