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Fluid-structure interaction
Kosík, Adam ; Feistauer, Miloslav (advisor) ; Richter, Thomas (referee) ; Fürst, Jiří (referee)
In this thesis we are concerned with the numerical simulation of the in- teraction of compressible viscous flow and an elastic structure in 2D. For the elastic deformation we use a 2D linear model and nonlinear St. Venant- Kirchhoff and neo-Hookean models. The flow is described by the compressible Navier-Stokes equations written in the arbitrary Lagrangian-Eulerian (ALE) form in order to take into account the time-dependence of the flow domain. The discretization of both the flow problem and the elasticity problem is re- alized by the discontinuous Galerkin finite element method (DGM). We focus on testing the DGM applied to the solution of the flow and elasticity prob- lems. Furthermore, we discuss the coupling algorithm and the technique, how to deal with the deformation of the computational domain for the fluid flow problem. Our work is motivated by the biomedical applications. Numerical experiments include numerical simulation of vibrations of human vocal folds induced by the compressible viscous flow.
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Hygrothermal processes in walls of wooden houses
Vencel, Lukáš ; Vlach, František (referee) ; Bečkovský, David (advisor)
This diploma thesis solves the problems of hydrothermal processes in walls of wooden houses and associated issues. A chosen were two apartment buildings, where they underwent exmerimental measurement of indor air, in order to determine the boundary conditions commonly boundary building evelope. Was followed by hygrothermal analysis of four commonly used constructions of wooden buildings in the Czech Republic, using various numerical methods. The quantity of information obtained from various numerical methods were analyzed individually. The final part of the thesis is devoted to experimental measurements of diffusion properties of materials. Namely foil vapor barrier, in terms of its influence on the perforation vapor diffusion resistance factor. Information obtained from the experiments were applied to re numerical analysis for walls with a foil vapor barrier. Followed by comparing both cases, in terms of changes hygrothermal behavior of structures with influence of perforation of the vapor barrier.
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Reinforcement concrete column strengthening via steel bandage
Stloukal, Štěpán ; Laníková, Ivana (referee) ; Šimůnek, Petr (advisor)
The steel bandage is an economical and effective widely used method for strengthening RC columns. Diploma thesis reviews most common design proposals for the types of the bandage with directly loaded and not directly loaded steel angles. This work also includes a comparison of the different constitutive laws for confined concrete. In order to simulate real behaviour of strengthened structure the numerical analysis has been carried out using non-linear software ATENA. According to the European standards and adopted hypotheses the simplified analytical model has been derived to be able to calculate load-bearing capacity of a strengthened column under normal force and bending moment. The proposed model considers the contribution in confinement pressure caused by steel bandage and the contribution of directly loaded angles. In addition, the direct application on real frame structure has been performed.
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Numerical Analysis of Influence of Electromagnetic Fields on Small Airplanes
Řezníček, Zdeněk ; Hazdra,, Pavel (referee) ; Karban,, Pavel (referee) ; Raida, Zbyněk (advisor)
This thesis deals with numerical analyses of electromagnetic fields on small aircraft with composite parts as an innovative way for assessment of their inherent protection against electromagnetic effects of outside environment in all development stages. It is concentrated for procedures of creation of geometrically and materially complex models for simulating calculations in the time as well as frequency domains, execution of the simulations itself and comparisons of results between the internal electromagnetic calculations and executed experimental tests. Achieved results were verified on a simplified reference model of aircraft's fuselage and two aircraft prototypes VUT100 and EV-55 of the company Evektor, spol. s r. o.
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Numerical Modeling of Periodical Structures
Nešpor, Dušan ; Bartušek, Karel (referee) ; Brančík, Lubomír (referee) ; Fiala, Pavel (advisor)
The thesis discusses the dynamic electromagnetic field on periodic structures. The author focuses on three principal types of resonant structures, considering their application possibilities. In general, these types can be individually defined as follows: materials exhibiting a negative refractive index of the incident electromagnetic wave; structures with gradual changes in impedance, characterised by their usability as reflectionless surfaces; and periodic structures able to conveniently shape the magnetic field distribution. Materials of the third group within the above-shown short list facilitate the fabrication of magnetoinductive lenses for nuclear magnetic resonance. The presented analysis of the properties of periodic resonant structures is mainly based on numerical models utilising the finite element method, and this approach is combined with both the derivation of the corresponding analytical relations and an experimental measurement of the non-radiating component of the electromagnetic field. The thesis includes a physical description of the basic elements of periodic resonant structures. Physical properties of the elements were examined in detail via numerical analysis. In the course of the research, the data acquired through this analysis and the related experimental measurement enabled the author to propose a method for optimising the most widely used resonant structures. Moreover, several new versions of resonant elements, structures, and fabrication techniques were also designed. The results obtained from the numerical analyses carried out to examine the central physical properties of the fabricated structure samples were all verified via the designed method for measuring the non-radiating component of the magnetic field.
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Stone columns - importance of arch effect
Vanko, Peter ; Zdražil, Karel (referee) ; Miča, Lumír (advisor)
The aim of the the thesis is to study the development of arch effect depending on the change of the various parameters such as grid of columns, height of embankments, material of embankment fill and material of columns. The first phase of work summarizes theoretical knowledges of stone columns and arch effect. The next phase deals with analysis of the effect of arch using numerical modeling. In the next part of the second phase circular tank based on stone columns will be modeled, where deformations and stress on columns will be monitored in changing constitutive model and applying substitute characteristics. Obtained results will be evaluated in conclusion.
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Static load test and the assessment ceiling of reinforced concrete structure built in the 1st half of 20th century
Málek, Jaroslav ; Láník, Jaromír (referee) ; Žítt, Petr (advisor)
This master thesis deals with static load test and static assessment of selected segments of reinforced concrete ceiling construction of the Hennebique system at the Faculty of Arts at Masaryk University in Brno. This thesis contains: the execution of the static load test, the data evaluation of the static load test and the data evaluation of the complementary laboratory testing, geometric orientation of bearing elements, the checking of the ceiling placement in the peripheral position, and the diagnosis of the reinforcing of the construction. This thesis also includes the static assessment according to various standard norm rules and the numerical analysis in ATENA software program.
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Equivalent circuit realizations of the simple chaotic oscillators
Kobza, Jaromír ; Dostál, Tomáš (referee) ; Petržela, Jiří (advisor)
The aim of this paper is to introduce with basic theory the problems encountered when considering the circuit implementation of autonomous RC chaotic oscillator with nonlinearity. All oscillator prototypes are based on one type of universal oscillator circuit. This circuit is able to generate a lot of attractors on condition of different entrance parameters. The design is based on a mathematical simulation, which includes the generation of electronic circuit values. The work is focused the transformation of these values to operational circuit configuration and simulation in a circuit simulator. The final task is to acquire chaotic attractors. Oscilloscope and spectrum analyser photos will verify the operation.
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Experimentální a numerická analýza interakce vlhkosti s tepelnou vodivostí dřeva
Kopal, Ondřej
This thesis deals with the analysis of thermodynamic approaches for the determination of thermal conductivity and moisture content of wood in a living tree. The work is divided into two main parts, which are numerical simulation and experimental evaluation of the measured data. Numerical simulation is carried out in a computer software based on the definite element method. There was a model describing the temperature field in the wood implemented into the software. Subsequently, this model was used for numerical analysis of methods allowing the derivation of thermal conductivity and moisture content of wood by measuring the temperatures of the heated part in the sapwood of the tree wood.
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