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Dancing liquid - vibration eigenmode shapes of liquids
Urban, Ondřej ; Pochylý, František (referee) ; Rudolf, Pavel (advisor)
This bachelor's thesis deals with phenomena connected with vertically oscillating liquid layer, particularly with Faraday waves and liquid atomization. More in detail it deals with the linear mathematical model for vertically oscilating inviscid and incompresible liquids by Benjamin & Ursell (1954). It also presents the appearance of these and other phenomena connected with liquid vibration in practical applications. Furthermore, results of experiments are presented. Their aim was to find some eigenmode shapes using the linear model and also to document some of their properties. Final part is aimed to the design of an experimental device for visualization of vibration eigenmode shapes of liquids.
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Dynamic analysis of structure with seismic loads
Šnajdárková, Jana ; Nevařil, Aleš (referee) ; Vlk, Zbyněk (advisor)
This thesis focuses on creation of two models of high-rise construction - beam and shell. A dynamic analysis is performed on these models. The selected program is RFEM software and the created high-rise construction is Hearst Tower skyscraper, which is interesting for its diagrid system around its perimeter. There is described process of creating both models and associated problems. Dynamic analysis is performed using standard EN 1998-1. There belongs calculations of sufficient number of modal shapes, spectral analysis and time analysis. Then the results are compared on selected point on the both models.
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Analysis of the rotor packet prestress on the rotor critical speed
Lekeš, Filip ; Huzlík, Rostislav (referee) ; Lošák, Petr (advisor)
The presented diploma thesis deals with the modeling of the rotor packet in dynamic calculations and analysis of the influence of the packing pressing force on the critical speed of the electric motor. The thesis can be divided into three main parts. The first part discusses the current level of rotor packet modeling in dynamic calculations and also deals with analytical theories for subsequent experimental tests. The second part describes the implementation of two experiments to determine the equivalent modulus of elasticity. The first experiment is a four-point bending test and the second is an experimental modal analysis. The third part is used for comparing the results obtained from experimental tests and describes the calculation of the critical speed of the rotor package pressed on the shaft by the finite element method.
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Calculation of natural frequencies of a bar system using finite element method
Svoboda, Petr ; Kubík, Petr (referee) ; Návrat, Tomáš (advisor)
The task of the presented bachelor thesis has been to program an algorithm of the finite element method to calculate natural frequencies of beam systems. To solve this problem a freely available SW products (Python, libraries NumPy, SciPy, Fortran compiler etc.) should have been primarily used and thereby to check possibilities of freely available SW product application in science purposes in the field of the Continuum Mechanics tasks. For a functionality verification of the program the ANSYS code is to be used.
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Dynamic analysis of bridge construction
Kinclová, Radka ; Nevařil, Aleš (referee) ; Vlk, Zbyněk (advisor)
The objective of this diploma thesis is a dynamic analysis of a cable-stayed walkway. The RFEM structural analysis software is used for the calculation. Design principles of the structure are explained and analysis of the construction phases is then performed. The eigenmodes of the structure are calculated for various material combinations. The thesis examines the effects of moving loads and earthquake effects using several different methods. A comparison of the various loading effects on the structure and also the calculation methods is presented at the conclusion.
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Modal analysis experimental method verification
Pop, Miroslav ; Lošák, Petr (referee) ; Houfek, Martin (advisor)
This diploma thesis deals with the issue of operational modal analysis, which is one of the newer areas of structural dynamics that makes it possible to estimate modal properties of structures directly during their operation. The aim of this work is to create theoretical basis of operational modal analysis, more specifically of Frequeny Domain Decomposition method. Furthermore, apply this method to a selected structure and verify the achieved results using computational modelling and experimental modal analysis. The technique of dividing the experiment to separate measurements using reference sensor was used. Evaluation of the operational modal analysis was performed using self-created function for the MATLAB software and using the commercial PULSE Operational Modal Analysis software. Obtained results were verified by computational modelling and experimental modal analysis.
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Exact solution of bending vibrations of beams
Machoň, Matěj ; Habán, Vladimír (referee) ; Havlásek, Michal (advisor)
The bachelor’s thesis deals with the analytical determination of eigenfrequencies and mode shapes of the prismatic beam. The solution is compared with the experimental data and validated. The analytical relations for determination of eigenfrequencies and mode shapes of prismatic beam expressed by basic functions and also by Krylov functions are the results of the thesis.
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VUT 081 Kondor aircraft aeroelastic analysis
Talanda, Tomáš ; Šplíchal, Jan (referee) ; Juračka, Jaroslav (advisor)
This master thesis deals with VUT~081~Kondor aircraft flutter analysis. This aircraft is being designed at the Institute of Aerospace Engineering, Faculty of Mechanical Engineering, Brno University of Technology. The thesis contains detailed aircraft description, natural frequency and normal modes computation as well as aircraft structure flutter analysis and critical flutter velocity determination. Some structure improvement recommendations have been given in order to increase the critical flutter velocity and to fulfil the CS-VLA regulation requirements.
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Study of dynamic effect on a bridge structure with moving loads
Zavřelová, Michaela ; Martinásek, Josef (referee) ; Vlk, Zbyněk (advisor)
The goal of the master thesis is a dynamic parametric study on the dynamic effects of high-speed train using the HSLM-A load model on a railway bridge. The calculation model is processed, in RFEM 5.29.01 with RF-MOVE module and prerelease versions RFEM 6 and RSTAB 9, as a 2D member in the XZ plane. Furthermore, static load cases and load models LM 71 and HSLM-A are created. The HSLM-A load model is processed for universal trains A1-A10, which each cross the railway bridge at a total of 15 speeds ranging from 120 km/h to 400 km/h. A detailed parametric study of the dependence of the maximum deformation and acceleration in the Z direction on the speeds of each train set is performed. Modal and time history analysis is used in the parametric study. Part of the work is to determine the resonance region.
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