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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Výroba rohového dřezu / Production of a corner sink

Soldán, Josef January 2019 (has links)
This diploma thesis if focused on the production of a corner sink from stainless steel sheet 1.4301. Based on analysis of manufacturing possibilities the best solution is to produce corner sink by a conventional tool in serval operations, which was the main focus of theoretical part of this thesis. In addition, this choose is in conform with assignment of this diploma thesis. Practical part of this thesis was focused on check of technologicity followed with design of suitable shape of sheet for deep drawing. Further calculation of amount of required draws in specific drawing operations, calculation of drawing forces and works and calculation of parameters of drawing tool. These calculations were checked by numerical simulation which discovered possible defects whereupon the shape of corner sink was modified in order to limit these defects. Based on these calculations the universal drawing tool was designed. In the ending of this thesis the techno-economic evaluation was made which confirmed the economic advantage of this universality.
212

Algoritmizace návrhu počátečního tvaru membránových konstrukcí a jejich statická a dynamická analýza / Algorithms for design and analysis of membrane structures

Lang, Rostislav January 2019 (has links)
Předkládaná práce se zabývá problematikou navrhování membránových konstrukcí, a to především s ohledem na vývoj potřebných výpočetních nástrojů v rámci MKP programů. Po uvedení základních fyzikálních požadavků jednotlivých kroků při navrhování těchto konstrukcí budou dále prezentovány vybrané či navržené algoritmy. Kapitola form finding se zabývá analýzou tvaru membránových konstrukcí. Rovnovážný tvar je odvozen od požadavku na výsledné předpětí, specifikované okrajové podmínky a aplikované zatížení. Obecně se ale tento proces zabývá i samotným hledáním rovnovážné soustavy sil v prostoru. V důsledku této skutečnosti jsou součástí popisované analýzy také vhodné stabilizační metody. V této kapitole budou prezentovány jak zvolené postupy, tak i navržená stabilizační technika specializovaná na hledání tvarů kuželových membrán. Dále je také popsán navržený algoritmus pro řešení úloh optimalizujících tvary ohybově tuhých konstrukcí, které jsou spjaty s hledáním labilních rovnovážných konfigurací. Kapitola structural analysis je zaměřená především na fenomén vrásnění membrán. Tato náhlá ztráta stability silně ovlivňuje statickou i dynamickou odezvu membránových konstrukcí. V rámci této kapitoly je představena a verifikována navržená výpočetní metoda, modulárně aplikovatelná na lineární, nelineárně elastické i plastické materiály používané pro uvedené konstrukce. Kapitola cutting pattern generation se zabývá výpočtem střihových vzorů, nezbytných pro výrobní proces membránových konstrukcí. Pro tento proces je v rámci předkládané práce navržena kombinace dvou různých metod. Zvolená posloupnost algoritmů cílí na optimalizaci poměru rychlosti, obecnosti a přesnosti výpočtu. Zmíněné kapitoly jsou doplněny jednotlivými příklady, analyzovanými pomocí popisovaných algoritmů, které demonstrují konkrétní fyzikální problémy či nezbytné implementační procesy.
213

Koncepce řadového zážehového motoru / Concept of an In-line Spark-ignition Engine

Kočvara, Antonín January 2020 (has links)
This thesis deals with comparison of straight four-cylinder petrol engine with a displacement of 1,5 litres and its three-cylinder alternative, which is based on a four-cylinder. The thesis starts with a research, where are examples of some currently manufactured engines. The research is followed by design of both engines, where the design of the crank mechanisms is made more in detail. After that, both crank mechanisms are subjected to dynamic analysis using FEM and MBS methods. The thesis ends with comparison of both engines in terms of crankshaft load, mass and dimensions.
214

Výpočtová simulace tlakové zkoušky kovové pěny s otevřenými buňkami / Computational simulation of the compression test of the open cell metal foam

Homola, Václav January 2020 (has links)
The thesis presents computational simulation of compression test of a nickel foam and the 3D reconstruction of micro-CT images was utilized to generate the foam’s model of geometry. Explicit FEM is used to simulate compression test using software tool LS-DYNA and the stress–deformation curve is obtained together with deformed model’s mesh used for subsequent analysis. Sensitivity analyses were performed to configure the model and ensure best fit with values obtained during real-life experiment. The ANSYS Classic environment was then used to simulate tensile test of the foam compressed to various thicknesses. The tensile moduli in three mutually perpendicular directions of nickel foam were computed and the results were compared to experimental values as well. The results of tensile test simulation revealed considerable anisotropy of the foam’s elastic behavior. It can be said that the measured experimental data correspond very well with the elastic properties obtained from simulation up to certain level of compression. Analysis of the relationship between the element size and tensile moduli showed a significant difference between fine and coarse mesh. The optimal level of discretization and the overall model configuration ensuring high level of accuracy is proposed in this thesis.
215

Modifikace přistávacího zařízení letounu Irbis / Modification of the landing gear of the Irbis aircraft

Forman, Tomáš January 2021 (has links)
This master thesis deals with the landing gear rebuild from tail gear to nose gear of the M-4 Irbis aircraft. The first chapter presents the aircraft in its current state and includes some technical data, too. The theoretical information about types of landing gears, its characteristics, pros and cons and the typical representatives for each type of landing gear are mentioned in the second chapter. The third chapter is about landing gear loads that occur during landing and about the load calculation according to UL 2 regulation. The following chapter shows the construction of the new landing gear, including some of the suggested, but not realised, designs. In the fifth chapter, there is a landing gear strength calculation of some of the gear components. The calculation is analytical and then uses FEM. The very last chapter then shows the effect of new landing gear on the centre of gravity in its extreme positions. The chapter also compares aircraft masses with both landing gears.
216

Využití programu ANSYS Workbench v silnoproudé elektrotechnice / Utilization of ANSYS Workbench program at power electrical engineering

Partl, Tomáš January 2009 (has links)
In its first part this Master´s thesis describes creation of electronic database design in Raster Design 2009 program as an effective form of storage only for paper documentation. The second part of my thesis provides calculation of primary and secondary winding of current instrument transformer of over-current conduit through the winding and influence on other parts of transformer i.e. error of transformer or increasing magnetic induction core and others. The last third part is focusing on usage of ANSYS Workbench in power electrical engineering. The thesis shows specific example of warming of current instrument transformer (thermal analysis) and comparing the results with theoretical (calculated) values.
217

Modelování přechodných dějů u synchronních stroju pomocí MKP / FEA modelling of synchronous machine

Ficza, Tibor January 2010 (has links)
Táto práca sa zaoberá s modelovaním synchronného stroja s permanentnými magnetmi pomocou metody konečných prvkov. K modelovaniu sme si zvolili 3 fázový synchronný stroj s permanentnými magnetmi na povrchu rotora z firmy VUES. Najprv vypočítame parametre stroja a potom spravíme statický model pomocou programu FEMM a Matlab a budeme hladať možné riešenia na 2D dynamický model. Pomocou programu Ansys Workbench spravíme 3D model tohoto stroja budeme a porovnávať výsledky simulácie.
218

Výpočet a měření parametrů asynchronních motorů / Calculation and measurement of induction motor parameters

Nekovář, Martin January 2012 (has links)
The theme of this master´s thesis is calculation and measurement of the parameters of induction motor. The thesis is divided into several parts. The first and the second part describes the general construction and operating principle of asynchronous motors. The construction includes a description of each part of induction motor, which consists of stator and rotor. The thesis deals with three-phase symmetrical and asymmetric single-phase motors. Principle of operation with using the rotating magnetic field, which is circular at three-phase motors, single phase motors have field elliptical shape. The next part contains the motor replacement scheme. The fourth part contains the calculation of motor´s parameters through the formulas. In this part the procedures for obtaining parameters of the replacement scheme of induction motor are defined. The process of calculating the parameters of the motor replacement scheme of threephase asynchronous motor is created according to given documentation is the next part for the certain type. The next content of the thesis describe finite element method, simulation and measurement of asynchronous motors to get of parameters from no-load and short-circuit test. The comparison of the results from measurement, analytical calculation and from simulation is given in the last chapter.
219

Řešení stability svahu v náročných geotechnických podmínkách / The Analysis of Slope Stability in Difficult Geotechnical Conditions

Wetterová, Alice January 2012 (has links)
Aim of the diploma thesis is design elements of slope stabilization in accordance with the planned highway D3 in Slovakia section of Cadca, Bukov - Svrčinovec and relocation of a local road. Objective subject is situated on the slopes of Cadca. In diploma thesis is an analysis of the area with the proposed stabilizing elements in the 5 GEO FEM, their assessment, including determining the overall stability of the territory according to the degree of safety.
220

Modelování odezvy zkušebních těles ze stavebních materiálů při lomových experimentech / Modelling the response of building material specimens during fracture tests

Navrátil, Petr January 2012 (has links)
The thesis focuses on the computational simulation of wedge splitting test of a concrete specimen by using finite element method. Different levels of numeric model for different notch depth and for different position of support are solved. Depending on the depth of a notch and difference of configuration, the crack paths and responses to an exterior load on a crack mouth opening displacement are evaluated.

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