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Hydraulicky poháněné česle pro malou vodní elektrárnu / Hydraulic powered screens for small hydropower plantSnášelová, Dana January 2017 (has links)
This diploma thesis deals with the design of hydraulic cleaning machine of fine screens located in the supply channel of small hydropower plant. The part of this thesis is also the design of hydraulic circuit and strength analysis using finite element method. The thesis also deals with the optimal debris removal. The thesis is attached by drawing documentation of selected parts of the mechanism.
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Výpočet rozložení teplotního pole v elektrickém stroji / Calculating the temperature field distribution in an electrical machineHaratek, Jiří January 2017 (has links)
This diploma thesis deals with methods used to determine the temperature field distribution within an electric machine. The first part is focused on methods of temperature measurement, generation and transfer of the thermal energy within the electric machine, asynchronous motor in particular. The thesis describes classical methods of temperature measurement and it also deals with ANSYS Workbench finite element method for thermal analysis of the motor. The final part of the thesis is focused on a comparation of all discussed methods with respect to results of thermal test for real asynchronous motor and concludes the most proper method.
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Deformačně napěťová studie Burch-Schneiderovy dlahy / Strain Stress Study of Burch-Schneider SplitŘehák, Kamil January 2018 (has links)
This thesis deals with problems of the hip endoprosthetics area, namely total endoprosthesis (TEP) with Burch-Schneider (BS) split, in which there are many problems in clinical practice. The hip joint load depends on the patient weight and the performed activity. Sedentary job, little exercise, a lot of stress or poor eating habits and overweight associated with it affect negatively hip joint. Increasing hip joint wear and its pain in movement is necessary in several cases to be solved by a surgical procedure in which TEP is applied. When selecting and subsequently applying individual TEP, it is important to pay attention to creating conditions which will allow good fixation. In case of worse mechanical properties of bone tissue, it is very problematic to ensure stability of the implant. Based on several classifications which assess the degree of hip joint damage, it is possible to select a suitable TEP. The BS split, on which this work is focused, is dominantly used in cases of large defects in the acetabulum area. The use of this cage allows to bridgelarge defects and create a new centre of rotation of the hip. Knowledge of the mechanical properties of hip bone tissue can significantly affect the prediction of BS split damage. For this purpose, it was necessary to perform a biomechanical study, which is focused on the influence of worse mechanical properties of bone tissue on BS split failure. The computational modelling using finite element method implemented in the ANSY S software was used for the solution, which enables to solve the mechanical interaction between bone tissue and TEP with BS split. Due to the absence of bone tissue data before application of TEP with BS split, the variants before application of TEP and after application of resurfacing and standard TEP were solved. All variants were solved with the material properties of bone tissue that were determined based on CT images. In addition, all variants were solved for the case of degraded mechanical properties. Based on the numerical simulations results and the Mechanostat hypothesis, a bone tissue analysis of the hip joint was performed before and after application of TEP and TEP with BS split. The results show the influence of the computational model level, which considers the distribution of bone tissue through the inhomogeneous model of the material. Therefore, the degraded mechanical properties have a major impact on the stability and strain of the BS split, particularly in the cranial part of the acetabulum.
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Výzkum v oblasti konstrukčních prvků a dimenzování cementobetonových krytů / Research in the field of construction elements and design of concrete pavementsGrošek, Jiří Unknown Date (has links)
The presented dissertation is focused on research in the field of dowels and design of concrete pavements using the finite element method. The theory part describes the history and the currently used techniques in the world and in the Czech Republic. The practice part of the dissertation contains a description of design methods, diagnostics of concrete pavements by using FWD and a description of laboratory tests on beams with inserted dowels. The results of measurements and modelling are verified on real operating conditions on testing fields. Based on the dissertation results, the amendment of the Czech standard ČSN 73 6123-1 regarding the position of dowels were proposed and approved. In addition, methodological guidelines of the Ministry of Transport regarding the measurements of the dowels and tie bars position and diagnostic by FWD was approved. The conclusion of the work summarizes and emphasizes the results of the dissertation.
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Porušování vybraných stavebních kompozitů v blízkosti rozhraní plniva a matrice / Fracture of selected building composites in the vicinity of aggregate-matrix-interfaceVyhlídal, Michal January 2018 (has links)
The interface between aggregate grains and matrix in cementitious composites is their weakest element. The topic is particularly significant in the case of high performance and high strength concrete technology for which the eliminination or reduction of these weak links are necessary. The aim of this thesis is to determine the influence of the interface on the fracture behaviour of the cementitious composites. The fracture experiments were performed for this purpose and were complemented by the nanoindentation’s results and scanning electron microscopy results. Numerical model was created in ANSYS software on the basis of these data and the fracture toughness values of the interface were evaluated by means of the generalized fracture mechanics principles. Conclusion of the thesis is proof that the interface properties have a significant influence on the fracture behaviour of cementitious composites.
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Pravděpodobnostní modelování smykové únosnosti předpjatých betonových nosníků: Citlivostní analýza a semi-pravděpodobnostní metody návrhu / Probabilistic modeling of shear strength of prestressed concrete beams: Sensitivity analysis and semi-probabilistic design methodsNovák, Lukáš January 2018 (has links)
Diploma thesis is focused on advanced reliability analysis of structures solved by non--linear finite element analysis. Specifically, semi--probabilistic methods for determination of design value of resistance, sensitivity analysis and surrogate model created by polynomial chaos expansion are described in the diploma thesis. Described methods are applied on prestressed reinforced concrete roof girder.
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Polyfunkční dům – železobetonová nosná konstrukce / Reinforced concrete structureTesař, David January 2018 (has links)
The aim of the master‘s thesis is static and structural design of polyfunctional house. The load will be determined according to ČSN EN 1990. The finite element method will be used for the calculation of internal forces. The design will be dimensioned according to ČSN EN 1992. Text part, static calculation and shape and reinforcement drawings will form the output of this work.
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Analýza svarů s využitím metody konečných prvků / Analysis of welded joints using Finite Element MethodŠtěrba, Martin January 2018 (has links)
This diploma thesis is concerned with the numerical analysis of welded aluminim structures. In these structures, there are significant decreases in the mechanical properties at the area of the weld and in the heat affected zone as a result of welding. Within this thesis, simulations of quasi-statically loaded welded joints made from EN AW-6082 T6 alloy were performed to investigate the load capacity and ductility of these joints. Computations were performed using a programme system based on an explicit finite element method. To describe material anisotrophy, a nonlinear material model called the Weak texture model was chosen. Material properties of the weld and the heat affected zone were considered to be different from base material. The required material parameters were adopted from available literature, however, material tests and indetification procedure of these parameters were described. In comparison with the experimental data, the results of the numerical simulations showed a relatively good ability of models to capture load capacity of studied welded joints. Nevertheless, due to mesh sensitivity of models caused by localization of deformation, it was not possible to determine ductility of these joints.
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Stanovení hodnot vstupních parametrů pokročilých materiálových modelů s využitím optimalizačních metod / Determination of input parameters of advanced soil constitutive models using optimization methodsKoudela, Pavel January 2018 (has links)
Choice of the constitutive model and determination of input parameters are necessary for a successful application of numerical methods in geotechnical engineering. Higher complexity of modern constitutive models results in an increase of the number of input parameters and time requirements for their calibration. Optimization methods are a possible solution for this problem. An application in which metaheuristic optimization method Particle swarm optimization (PSO) is involved is presented in this thesis. Critical review and testing of various PSO alternatives was performed in the first part of this thesis. The most efective PSO alternatives were chosen. In the second part connection between PSO algorithm and finite element solver was prepared. Automatization of determination of constitutive models input parameters was performed on three boundary value problems: laboratory test (oedometer), in-situ test (pressuremeter) and geotechical construction (retaining wall). Three types of constitutive models are used. Linear elastic-perfectly plastic Mohr-Coulomb model, elastoplastic non-linear Hardening soil model and Hardening soil - small strain model.
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Pohon pro bezucpávkové čerpadlo / Drive for seal-less pumpPruša, Radomír January 2018 (has links)
The aim of this thesis is to design a drive for seal-less centrifugal pump. Designed motor with axial magnetic flux is a double-sided structure with an internal coreless stator. The construction of the seal-less pump is based on a patent no. 17818, which was created at the Victor Kaplan Department of Fluid Engineering BUT. Potential use of this assembly is mainly in the food industry, possibly in the field of chemically aggressive liquids. The whole design is based on coordination between analytical equations and finite element method of the software ANSYS Maxwell. The temperature ratios inside the motor were investigated when cooling with air by the iterative solution of thermal circuit. The work includes research on the topic of constructing the axial machines and their applications in pumps. A comprehensive specification of the entire seal-less centrifugal pump is given in Chapter 4.
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