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A study of the stress field near the stress concentrator at the bi-material interface
Krepl, Ondřej ; Klusák, Jan (referee) ; Profant, Tomáš (advisor)
The aim of this work is the solution of problems of the stress distribution near bimaterial notch tip or eventually the crack impinging orthogonaly the bimaterial interface, determination of stress singularity exponent. The first part is concerned with basics of linear elastic fracture mechanics, i.e. Irwin's concept of stress intensity factor. The second part is devoted to description of anisotropic materials by complex potencial theory. The final part is focused on calculation of eigenvalues of both isotropic and anisotropic materials and application of LES formalism on the calculation of stress singularities of the bimaterial ortotropic notch or the crack impinging orthogonaly the bimaterial interface.
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REINFORCED CONCRETE TANK
Beran, Jakub ; Jeneš, Rostislav (referee) ; Šulák, Pavel (advisor)
The aim of the bachelor thesis is a static design of an reinforcement tank. The internal forces are calculated by FEM programme Scia Engineer 16.1 with a SOILIN modul interacting with a subsoil model. The internal forces are verified by a manual calculation. The load-bearing elements are designed with these forces. The structural assessment report is designed to ultimate limit state and service limite state – service limit state of crack. Another report considers ground water occurring. The static report deals with different time of concreting foundation slab and walls. This is the reason why shrinkage is very important for internal forces and their values. The objective of the project is to design the tank without cracks in concrete. The limit width of cracks is wk= 0,3 mm by EC 1992-1-1.
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Evaluation of fracture test of selected core-drilled cylindrical specimen
Halfar, Petr ; Sobek, Jakub (referee) ; Keršner, Zbyněk (advisor)
The diploma thesis deals with effective crack model for a cylinder specimen with an chevron-shaped notch, loaded by a three-point bending. The first part of the thesis is theoretical and the it describes the use of fracture mechanics for quasi-brittle materials – concrete and rocks. Furthermore there is described the linear elastic fracture mechanics and founding the geometry function for a different geometries of fracture tests. The second part describes the FEM program, which was used to calculate the fracture parameters, that were used to determine the length of the effective crack and how the program was tested before it was used. The last part describe calculations of fracture toughness by using the effective crack model on selected rock and concrete specimens.
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Design of the concrete sewage plant
Štramberský, Martin ; Strnad,, Jiří (referee) ; Zich, Miloš (advisor)
The subject of my bachelor's thesis is a static design of a sewage plant reservoir, dimensioning and examination of the construction part for Capacity Limit State and Applicability Limit State. Design documentation is included in the project. The aim of this thesis was to design the reservoir in such a way that there would be no cracks in the concrete. The calculations were carried out in accordance with Eurocode 2.
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Fracture Toughness of Metallic Materials and its Testing
Kosek, Lukáš ; Zapletal, Josef (referee) ; Němec, Karel (advisor)
The purpose of the work is to introduce the basic of the fracture toughness of metallic materials and its measuring under the conditions of the plane strain. There are shown essential concepts of the linear elastic fracture mechanics, which is used for the description of the material behavior at fracture of the material with a crack. It defines stress intensity factor and describes the main elements influencing the fracture toughness. Furthermore, the work contains the particular testing methods, specimens and testing equipments. In the conclusion it recapitulates the availability and the application of the linear elastic fracture mechanics.
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Sewage pumping station
Čožík, Martin ; Perla, Jan (referee) ; Strnad, Jiří (advisor)
The subject of my bachelor’s thesis is static design of a sewage plant reservoir, dimensioning and examination of the construction part for Capacity Limit State and Applicability Limit State. Design documentation is included in the project. The aim of this thesis was to design the reservoir in such a way that there would be no cracks in the concrete. The calculations were carried out in accordance with Eurocode 2.
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Analysis of the three-dimensional shape of the crack in the cantilever beam
Ozimák, Eduard ; Ševeček, Oldřich (referee) ; Majer, Zdeněk (advisor)
The bachelor thesis deals with the numerical calculation of the stress intensity factor using the finite element method and the subsequent modelling of the crack face shape on a simple beam in the ANSYS Mechanical APDL computational environment. In the introductory part of the thesis, the history and beginnings of fracture mechanics are described. Then, the basic theoretical knowledge and relationships needed when working with a body containing a crack are described. This is followed by an introduction to the finite element method. In the second part of the bachelor thesis, the procedure of performing numerical calculations and modelling in the ANSYS environment is described in detail.
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An aplication of the mathematical dislocation theory to the problem of the crack in the vicinity of the bi-material interface
Padělek, Petr ; Hrstka, Miroslav (referee) ; Profant, Tomáš (advisor)
The presented diploma thesis deals with a problem of the determination of the stress intensity factor of the finite length crack in the vicinity of the bi-material interface solved by the distributed dislocation technique. The work is divided into several parts. The first part is theoretical and includes basic concepts of the fracture mechanics, the crack behaviour at the bi-material interface, the formulation of the singular integral equation by virtue of the distributed dislocation technique, the Bueckner's principle, complex potentials and consequently the determination of the stress intensity factor. The second part is the theory application to the specific configuration of the crack of the finite length with respect to the bi-material interface and in the third part, there is carried out the solution of this problem for various configurations of the bi-material solved by the distributed dislocation technique and its comparison with the results obtained from the FE analysis.
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