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Trackside vibration energy harvester
Beňo, Martin ; Sosna, Petr (referee) ; Rubeš, Ondřej (advisor)
This diploma thesis is about the design of a vibrating energy harvester for a railway track. The railways are constantly being innovated and require a large number of sensors to achieve a high level of security and predictive maintenance. Such sensors need to be powered by a certain power source. A conventional energy source could be replaced by a vibrating energy harvester. The work discusses not only the analysis of suitable parameters, but also the realization of the energy harvester. At the end of the work, a functional concept is presented and the proven results are also taken into account.
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Dynamic model of nonlinear oscillator with piezoelectric layer
Sosna, Petr ; Lošák, Petr (referee) ; Hadaš, Zdeněk (advisor)
Tato diplomová práce je zaměřena na analýzu chování magnetopiezoelastického kmitajícího nosníku. V teoretické části jsou odvozeny diskretizované parametry, které popisují reálnou soustavu jako model s jedním stupněm volnosti. Tento model je následně použit pro kvalitativní i kvantitativní analýzu chování tohoto harvesteru. Frekvenční odezva harmonicky buzeného systému je zkoumána v dvouparametrické nebo tříparametrické analýze v závislosti na amplitudě buzení, elektrické zátěži a vzdálenosti mezi magnety. Posledně zmíněný parametr je v práci tím hlavním, proto je vliv vzdálenosti magnetů zkoumán také s pomocí bifurkačních diagramů. Tyto diagramy byly navíc použity k vytvoření oscilační "mapy", která pro každé zatěžovací podmínky ukazuje, jakou vzdálenost magnetů je třeba nastavit, aby bylo generováno nejvíce energie. Práce je doplněna o ukázky několika jevů, které mohou značně ovlivnit chování systému, pokud se nejdená o čistě harmonické buzení.
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Analýza Duffingova oscilátoru
Sosna, Petr ; Hadraba, Petr (referee) ; Rubeš, Ondřej (advisor)
This thesis analyses the simplest model of nonlinear oscillations, the Duffing oscillator. Methods of nonlinear dynamics are used for analysis of the Duffing equation which describes such oscillations. Numerical solution focuses on the dynamics of twin-well potencial oscillations. The effect of all the parameters of the Duffing equation on the system is shown. Coexisting periodic and chaotic attractors are discussed as well as possible bifurcations of the system. A bifurcation diagram for a specific system is created. The thesis concludes with simulation of basins of attraction for different values of excitation force and frequency.
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Parametric Resonance of Dynamic Systems
Gajdůšková, Vendula ; Sosna, Petr (referee) ; Hadaš, Zdeněk (advisor)
The Bachelor’s Thesis deals with the parametric resonance which is investigated from the physical point of view by means of pendulum models, for which the equation of motion has been developed and subsequent modelling has been performed. The brief introduction is followed by a theoretical chapter which deals with the physical substance of parametric resonance and in which chosen physical models are described. The practical part of the thesis begins with the following chapter devoted to chosen examples of parametric resonance in practice, showing its benefits and harmful attributes on selected examples. The fourth and the main part of the thesis contains a simulation model of parametric resonance for two pliantly bound pendulums. The concluding part of the thesis consists of the summary of findings, model results and the list of used resources, abbreviations, figures and table.
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Analysis of chaotic behavior in double pendulum
Brázda, Tomáš ; Lošák, Petr (referee) ; Sosna, Petr (advisor)
This thesis deals with the presentation of basic knowledge regarding chaos theory. There are mentioned several basic methods of dimension calculation as well as the overall use of this theory in various scientific disciplines. The main part is devoted to the complete analysis of a double pendulum. To initiate into the issue, this situation was outlined on a simple mathematical basis pendulum. There is derived a numeral system of two differential equations of second order to work with the double pendulum. Thanks to computer program Matlab there was created a fractal that represents chaotic behavior of the double pendulum. Knowledge acquired from dimension calculation was used here to classify the fractal and to work out its dimension. In addition there was analyzed impact of parameters of behavior in system. This overall chaotic behavior has been verified by the largest Lyapunov exponent and the 0–1 test, which identified areas, where this system behaves chaotically and where it is stable.
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Magnetic spring design for vibration energy harvester
Kobík, Martin ; Sosna, Petr (referee) ; Rubeš, Ondřej (advisor)
The thesis is concerned with a design of a magnetic spring which could be used in an energy harvester. A parametric computational model is created, which allows to simulate the spring‘s force-displacement relationship with chosen parametres, such as the position and dimensions of the magnets. Furthermore two coefficients are defined for evaluating the force-displacement relationship – the coefficient of nonlinearity and the coeficient of linearized stiffness. The coefficients are further used in the analysis of the effect of the change of parameters on the force-displacement relationship. After the analysis, specific parameters are chosen for the construction of demonstration device. The computational model is finally validated by the demonstration device.
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Parametric Resonance of Dynamic Systems
Gajdůšková, Vendula ; Sosna, Petr (referee) ; Hadaš, Zdeněk (advisor)
The Bachelor’s Thesis deals with the parametric resonance which is investigated from the physical point of view by means of pendulum models, for which the equation of motion has been developed and subsequent modelling has been performed. The brief introduction is followed by a theoretical chapter which deals with the physical substance of parametric resonance and in which chosen physical models are described. The practical part of the thesis begins with the following chapter devoted to chosen examples of parametric resonance in practice, showing its benefits and harmful attributes on selected examples. The fourth and the main part of the thesis contains a simulation model of parametric resonance for two pliantly bound pendulums. The concluding part of the thesis consists of the summary of findings, model results and the list of used resources, abbreviations, figures and table.
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Trackside vibration energy harvester
Beňo, Martin ; Sosna, Petr (referee) ; Rubeš, Ondřej (advisor)
This diploma thesis is about the design of a vibrating energy harvester for a railway track. The railways are constantly being innovated and require a large number of sensors to achieve a high level of security and predictive maintenance. Such sensors need to be powered by a certain power source. A conventional energy source could be replaced by a vibrating energy harvester. The work discusses not only the analysis of suitable parameters, but also the realization of the energy harvester. At the end of the work, a functional concept is presented and the proven results are also taken into account.
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Geopolitical Imagination and Security Perception in Japan
Sosna, Petr ; Hynek, Nikola (advisor) ; Kolmaš, Michal (referee)
This thesis deals with Japanese foreign and security policy through the optics of critical geopolitics, specifically the "geopolitics as culture" notion developed by Gearóid Ó Tuathail. Using this notion as an analytical framework, the development of Japan's foreign and security policy from the establishment of a modern Japanese state till present days is analyzed, with three main concepts being addressed: (1) foreign policy traditions; (2) geopolitical and geostrategic discourses; (3) and strategic and geopolitical culture. For reasons of narrowing the topic down and applying the concept more consistently, one specific element of Japanese foreign and security policy is at the centre of attention: Japan's "maritime identity". The goal of the thesis is to identify and characterize Japan's geopolitical imagination and attempt to determine if and how has this imagination been expressed in the country's security policy with regard to the maritime identity. Powered by TCPDF (www.tcpdf.org)
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Dynamic model of nonlinear oscillator with piezoelectric layer
Sosna, Petr ; Lošák, Petr (referee) ; Hadaš, Zdeněk (advisor)
Tato diplomová práce je zaměřena na analýzu chování magnetopiezoelastického kmitajícího nosníku. V teoretické části jsou odvozeny diskretizované parametry, které popisují reálnou soustavu jako model s jedním stupněm volnosti. Tento model je následně použit pro kvalitativní i kvantitativní analýzu chování tohoto harvesteru. Frekvenční odezva harmonicky buzeného systému je zkoumána v dvouparametrické nebo tříparametrické analýze v závislosti na amplitudě buzení, elektrické zátěži a vzdálenosti mezi magnety. Posledně zmíněný parametr je v práci tím hlavním, proto je vliv vzdálenosti magnetů zkoumán také s pomocí bifurkačních diagramů. Tyto diagramy byly navíc použity k vytvoření oscilační "mapy", která pro každé zatěžovací podmínky ukazuje, jakou vzdálenost magnetů je třeba nastavit, aby bylo generováno nejvíce energie. Práce je doplněna o ukázky několika jevů, které mohou značně ovlivnit chování systému, pokud se nejdená o čistě harmonické buzení.
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