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Modelling of dynamics systems with multi degrees of freedom
Ondra, Václav ; Donát, Martin (referee) ; Dušek, Daniel (advisor)
The aim of this work is for a dynamic system with multiple degrees of freedom to assemble and solve the equations of motion. In the beginning of work are summarized the basic knowledge about the dynamic oscillating systems, their distribution, method of mathematical description etc. In the following part of work are for the given set of particles assembled equations using Lagrange equations of the second kind. The solution of equation is made in mathematical system MAPLE for frequency domain. To determine the position of particles in time was used MATLAB. Research results are graphs of amplitude and frequency characteristics and graph of positions of particles in time. There is discussion on the influence of systems parameters on oscillation. The conclusion is a comparison of analytical solution with the solution of finale elements conclusion in ANSYS.
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Creation of database of stator core stiffness of rotational electrical machines
Podzemný, Zdeněk ; Donát, Martin (referee) ; Dušek, Daniel (advisor)
In this thesis is wrote up a complete procedure of stator core stiffness determination using finite element method (FEM), subsequently, the stator core stiffness database was created according to this procedure. In the next chapter is carried out a sensitivity analysis of one chosen stator core, which led to identifying parameters that affected its stiffness the most. Finally, a modal analysis of one synchronous machine was performed using FEM, in order to determine the effect of stator core stiffness on modal characteristics of the machine. Several modal shapes and corresponding natural frequencies were computed in this analysis, then only a few shapes with the highest core effect were chosen and compared.
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Stress strain analysis of a synchronous generator
Majdič, Petr ; Donát, Martin (referee) ; Dušek, Daniel (advisor)
This master thesis deals with an impact of particular static and dynamic forces and temperature strain on horizontal synchronous generator. In connection with this, a stress distribution in construction and an assessment of security to terminal state of flexibility and weariness is being solved together with finding the most critical places on horizontal synchronous generator.
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Analysis of vertical synchronous generator modal properties
Kornherr, Milan ; Donát, Martin (referee) ; Dušek, Daniel (advisor)
This Master´s thesis deals with the analysis of modal characteristics of the vertical synchronous generator. The goal of this work is to determine influence of individual parts of the generator on modal characteristics. Another part of this thesis contains analysis of different variants for storaging the generator and also structural modifications, which lead to the improvement of the modal properties. For modelation was used cumputional modeling in ANSYS.
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Aerodynamic noise of computers
Zouhar, Lukáš ; Dušek, Daniel (referee) ; Pellant, Karel (advisor)
This submitted thesis pursues a theme of decreasing the computer noise, especially focusing on the aerodynamic noise of the cooling fans, possibilities of decreasing the noise by fan optimization, using rubber bolsters and sound-isolating layers or construction changes in the very fans and their placing. We shall also aim on the relation between the created noise and the blade shape or rotation speed.
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Complex Analysis of Modal Properties of Rotating Electrical Machines
Donát, Martin ; Vlach, Radek (referee) ; Žiaran,, Stanislav (referee) ; Dušek, Daniel (advisor)
This dissertation thesis deals with the computational modelling of the dynamic response of the rotating electrical machine structure on the application of the magnetic forces. Apart from the dynamic response of the ideal symmetrical machine, the influence of the air gap eccentricity on the dynamics response is studied in this work. A basic type of the air gap eccentricity, which is caused by eccentric mounting of the rotor pack on the shaft of the rotor, is considered. The calculations the dependence of the magnetic forces on the time and a misalignment of the rotor pack are performed as first. The computational model of the magnetic field of the rotating electrical machine, which is based on solution of the electromagnetic coupled field analysis by finite element method, is used for this purpose. An analysis of the influence of the unbalanced magnetic pull and the stiffness of some parts of the machine on the modal properties of the machine is performed in the second part of this thesis. A third part of this thesis is focused on the calculation of the dynamic response of the machine during the steady state operation of the machine and the influence of the rotor pack misalignment on the dynamic response is studied. The obtained results showed that the tangential components of the magnetic forces, which act on the stator pack, excite significant torsional vibration of the stator. Besides the vibration of the stator of the machine, the influence of the rotor pack misalignment on the sound power of the machine, vibration of the rotor, loads of rotor bearings and air gap eccentricity is studied in this thesis.
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Web Application Penetration Testing Automation
Dušek, Daniel ; Polčák, Libor (referee) ; Pluskal, Jan (advisor)
Tato práce má dva cíle - navrhnout obecně aplikovatelný přístup k penetračnímu testování webových aplikací, který bude využívat pouze nedestruktivních interakcí, a dále pak implementovat nástroj, který se tímto postupem bude řídit. Navrhovaný přístup má tři fáze - v první fázi tester posbírá požadavky pro testovací sezení (včetně požadavků na nedestruktivnost) a připraví si nástroje a postupy, kterých při testování využije, následně začne s průzkumem. V druhé fázi využije dodatečných nástrojů pro zpracování informací z předchozí fáze a pro ověření a odhalení zranitelností. Ve třetí fázi jsou všechny informace překovány ve zprávu o penetračním testování. Implementovaný nástroj je postavený na modulech, které jsou schopny odhalení reflektovaného XSS, serverových miskonfigurací, skrytých adresních parametrů a skrytých zajímavých souborů. V porovnání s komerčním nástrojem Acunetix je implementovaný nástroj srovnatelný v detekci reflektovaného XSS a lepší v detekci skrytých zajímavých souborů. Práce také originálně představuje nástroj pro sledování postranního kanálu Pastebin.com s cílem detekce utíkajících informací.
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Redesign of Vibration Power Generator with Respect to Overall Volume and Weight
Vaněček, Michal ; Dušek, Daniel (referee) ; Hadaš, Zdeněk (advisor)
This work deals with improvement construction already of the vibration power generator design. The improvement his feature and search ideal construction with reference to material, proportions and power. Gain here mechanical properties, to come to what best tune up and development of new construction for improved check out characteristics as is achievement. Tuning up of correct parameters proceed by the simulation and modelling in ANSYS and MATLAB environment.
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