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Influence of Loading Frequency on Fatigue Properties of Structural Materials
Kašpar, Jan ; Němec, Karel (referee) ; Věchet, Stanislav (advisor)
This thesis analyse the influence of loading frequency on the fatigue of the structural materials. Low frequency loading (to the 200 Hz) has nearly no influence on the fatigue properties in almost all cases. Hight frequency loading (1 and more kHz) has major influence on the fatigue limit of the structural materials. This interference will disply like increasing of the fatigue limit. For example fatigue limit of steel is more affected by hight frequency loading than the cast-iron. Important aspect at hight frequency loading is rising temperature in the loading process. Rising temperature has negative influence on the fatigue limit of materials. Important aspect of the loading high frequency is possibility to achieved gigacycle regime of the fatigue (109 and more cycles), where should appear crack from below surface. This crack is call „ fish eye".
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Numerical simulation of failure of ceramic foams upon mechanical loading
Hanák, Jiří ; Skalka, Petr (referee) ; Ševeček, Oldřich (advisor)
The master’s thesis deals with a numerical simulation of failure of ceramic foams with open-cell structure and with understanding of conditions required for the failure of the structure under various mechanical loading conditions. To this purpose, the so-called stress-energy coupled criterion was utilized. The motivation for this thesis was to create a model able of the most accurate prediction of the ceramic foam strength in comparison with experimental observations. First part of the thesis is focused on the theoretical background required for solving the problem. More specifically there are mentioned methods of the foam material modelling, Linear Elastic Fracture Mechanic (LEFM) and coupled stress-energy criterion used for definition of the crack initiation. In the second part of the thesis, numerical Finite Element Analyses (FEA) whose main purpose was to determine critical conditions necessary for the initiation of strut failure within the foam structure, were performed. These pieces of knowledge were then used for creation of the numerical simulation algorithm of the mechanical test of foam material with regular cell pattern. Outputs of numerical simulations were at the end of this work compared with experimental results (of the compression test) made on the real Al_2 O_3 foams prepared by 3D printing technology and provided by the Institute of Physics of Materials Czech Academy of Science. It can be concluded that a good agreement between results of both approaches was reached and the prediction of the ceramic foam mechanical strength using the developed model is in the meanwhile the most accurate estimation from recently published approaches.
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Sensitivity Analysis of the Software AREBA for Simulation Dam Breaching Due to Internal Erosion
Kotaška, Stanislav
One of the causes of earth fill dam failure are internal erosion. To simulate these phenomena, a number of software are available to calculate the failure of an earth fill dams due to overtopping or due to internal erosion. For this purpose, software (SW) A Rapid Embankment Breach Analysis (AREBA) was chosen, for which a one-way sensitivity analysis was performed. The paper aims to understand the key geotechnical parameters input to the SW AREBA and their influence on the dam breach hydrogram, the size of the breach and also on the time characteristics. The most sensitive parameters influencing the outputs are the Manning´s roughness coefficient and the erodibility coefficient. These two parameters should be varied by the Monte-Carlo method in the AREBA.
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Numerical simulation of failure of ceramic foams upon mechanical loading
Hanák, Jiří ; Skalka, Petr (referee) ; Ševeček, Oldřich (advisor)
The master’s thesis deals with a numerical simulation of failure of ceramic foams with open-cell structure and with understanding of conditions required for the failure of the structure under various mechanical loading conditions. To this purpose, the so-called stress-energy coupled criterion was utilized. The motivation for this thesis was to create a model able of the most accurate prediction of the ceramic foam strength in comparison with experimental observations. First part of the thesis is focused on the theoretical background required for solving the problem. More specifically there are mentioned methods of the foam material modelling, Linear Elastic Fracture Mechanic (LEFM) and coupled stress-energy criterion used for definition of the crack initiation. In the second part of the thesis, numerical Finite Element Analyses (FEA) whose main purpose was to determine critical conditions necessary for the initiation of strut failure within the foam structure, were performed. These pieces of knowledge were then used for creation of the numerical simulation algorithm of the mechanical test of foam material with regular cell pattern. Outputs of numerical simulations were at the end of this work compared with experimental results (of the compression test) made on the real Al_2 O_3 foams prepared by 3D printing technology and provided by the Institute of Physics of Materials Czech Academy of Science. It can be concluded that a good agreement between results of both approaches was reached and the prediction of the ceramic foam mechanical strength using the developed model is in the meanwhile the most accurate estimation from recently published approaches.
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The Internet and copyright - the scope of liability of individual parties involved and modes of protection against piracy
Szpyrc, Daniel ; Dobřichovský, Tomáš (referee)
The thesis titled "The Internet and copyright - the scope of liability of individual parties involved and modes of protection against piracy" deals with both, the protection of copyright and the scope of liability of various actors in the Internet environment. The content of the thesis is divided into four chapters, which allows the reader to be gradually acquainted with the whole issue. The first part briefly mentions development of the Internet network and its incorporation into the Czech legal order. The second chapter is devoted to the copyright protection in the Internet environment. Its content focuses on the most common methods of use of the author's work via the Internet, which is a reproduction of the work and its publication. This chapter further describes the development and operation of data sharing through peer-to-peer systems. Furthermore, it also deals with the issue of downloading of the work and application of the statutory exemption from liability for personal use only. The scope of liability in the Internet environment is largely harmonized by European provisions. For this reason, the third chapter contains the development phase of liability of the Internet services providers in the European countries. The first part of the third chapter demonstrates different approaches to the...
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The Internet and copyright-the scope of liability of individual parties involved and modes of protection against piracy
Szpyrc, Daniel ; Žikovská, Petra (advisor) ; Wünschová Pujmanová, Alexandra (referee)
The thesis titled "The Internet and copyright - the scope of liability of individual parties involved and modes of protection against piracy" deals with both, the protection of copyright and the scope of liability of various actors in the Internet environment. The content of the thesis is divided into four chapters, which allows the reader to be gradually acquainted with the whole issue. The first part briefly mentions development of the Internet network and its incorporation into the Czech legal order. The second chapter is devoted to the copyright protection in the Internet environment. Its content focuses on the most common methods of use of the author's work via the Internet, which is a reproduction of the work and its publication. This chapter further describes the development and operation of data sharing through peer-to-peer systems. Furthermore, it also deals with the issue of downloading of the work and application of the statutory exemption from liability for personal use only. The scope of liability in the Internet environment is largely harmonized by European provisions. For this reason, the third chapter contains the development phase of liability of the Internet services providers in the European countries. The first part of the third chapter demonstrates different approaches to the...
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Proceedings for infringement of the TEU by the Member State and its changes after the Lisbon Treaty
Starostová, Klára ; Zemánek, Jiří (advisor) ; Svoboda, Pavel (referee)
The aim of this thesis is to give a detailed overview of the functioning and effectiveness of one of the main instruments which EU has to enforce and control the application of the EU law by its Member States, which are the infringement proceedings for breaching of the EU law in its newest form as provided by Art. 258 - 260 of the Lisbon Treaty. The thesis contains also two issues related to the main topic, the state liability for the breaching of the EU law towards individuals and the preliminary ruling with accordance to the art. 267 of the TFEU. Another part of the thesis is a detailed consideration of the EU Pilot Project, which should serve as a platform for better cooperation between the Member States and the Commission.
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The causes of damage of cuts and embankments
Pacholíková, Andrea ; Král, Jan (advisor) ; Lešner, Jeroným (referee)
Title The causes of damage of cuts and embankments Abstract Thisworkdealswithproblemsofstabilityofslopes,trenches,offcutsofcommunications,especiallyreasonsfor their damaging. There are briefly listed areas which are in Czech republic prone to sliding and described most common causes for damages of slopes. Author next describes several location, where were slope deformations documented. These locations are in Czech Republic and Maroco. Extent of deformations and their causes are described in this work and documented with photos.
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