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Analysis of Aeronautical Composite Structures under Static Loading
Cejpek, Jakub ; Juračka, Jaroslav (referee) ; Cabrnoch, Bohuslav (referee) ; Jebáček, Ivo (advisor)
Poměrně velké množství soukromých firem v České republice vyrábí lehká sportovní letadla. Značná část těchto letadel využívá kompozitní pružiny ve svých přistávacích zařízení. Tyto pružiny jsou buďto menší díly, absorbující energii (na příďové noze či ostruze), anebo jde celé pružnice hlavního podvozku. Všechny tyto pružiny sdílí základní charakteristiky: jsou vyrobeny převážně z jednosměrného kompozitu s významnou tloušťkou, hlavním druhem zatížení je ohybový moment a jsou očekávány velké deformace. Podobnou charakteristiku můžeme použít i při popisu hlavního nosníku křídla. Jak vypadá návrh a analýza takovýchto dílů? V zásadě jsou dvě možnosti. První z nich je poměrně jednoduchá analytická analýza, případně naprogramovaná v tabulkovém výpočetním prostředí. Nevýhody tohoto řešení jsou limitované možnosti výpočtu a jeho nízká flexibilita. Druhou možností je využít komerční konečno-prvkový systém pro analýzu, případně i pro optimalizaci. Pochopitelnou nevýhodou této možnosti je cena programu a obsluhy. Cílem této disertační práce je vytvořit program, jež nabídne třetí možnost, která umožní provádět zevrubnou analýzu řešených produktů bez nutnosti pořizovat nákladný software. Tento program zjednoduší a urychlí návrh a pevnostní kontrolu. Umožní uživateli rychle analyzovat více návrhových variant. Program dále bude zohledňovat specifika analyzovaných produktů (například velké deformace a lokální koncentrace napětí kolmo na vlákno). Z pohledu uživatele by program měl být jednoduchý na ovládání. Minimum množství vstupních dat a přehledné grafické rozhraní zajistí komfortní používání. Samostatně spustitelný program (bez instalace a bez podpůrného softwaru) zlepšuje rozšiřitelnost programu.
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Water regime of reclaimed and nonreclaimed heaps
Cejpek, Jiří ; Frouz, Jan (advisor) ; Kuráž, Václav (referee)
Summary: Great Podkrusnohorska spoil heaps in the Sokolov region in Western Bohemia is the largest spoil heaps in the Czech Republic, which was pour million tonnes of overburden soil surface mining of brown coal. The thesis is setting on the basic characteristics of the water regime and water balance of spoil heap soil and thus follows a series of previous works dealing with the comparative development of the reclaimed and unreclaimed area. The areas are long-term monitoring of soil moisture using a dielectric soil moisture meter total water regime was monitored by subsurface with gravitation lyzimeter, runoff and throughfall rainfall. Older unreclaimed plots as well as reclaimed plots have higher porosity, water field capacity and moistre than young sites, however there are limited by water deficiency in similatr way as young sites due to increase in wilting point. Keywords: Spoil heaps, Recultivation, Soil humidity, Water supply, Water balance
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The Protection of Economic Competition with Special Regard to Pricing
Cejpek, Jan ; Horáček, Vít (advisor) ; Eichlerová, Kateřina (referee)
Legal rules protecting the economic competition against abusive pricing practices are traditionally part of the public branch of competition law. Sensitive drafting of the law by legislator or the prudence of law interpretation by the competition authority or the court in the specific case predetermines the companies` willingness to develop dynamically on the relevant market. Legislation of the poor quality prospectively misleading decisional practice can lead in two extreme situations; on one side unlimited freedom for the dominant company, on the other side unfounded and excessive sanctions, which distract the companies` ambitions to achieve excellence. The topic - The Protection of Economic Competition with Special Regard to Pricing - is dealt in five chapters of the thesis. The aim of the paper is to analyze substantial components in each price form of abuse, solve the relevant questions of law with regard to case study concerning both the European and the Czech context and consider where the development of this law field currently results in. The methodology is mainly based on the comparative and critical research of the decisional practice. Chapter One surveys predatory pricing. It contains passage on the price-costs test, which is the major issue also for the following chapters of the study....
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Sandwich structure application on the formula car
Žídek, Tomáš ; Cejpek, Jakub (referee) ; Löffelmann, František (advisor)
The master thesis describes application of a sandwich construction for Formula Student car. It will replace the current tubular space frame according to FSAE rules. The introduction is focused on the information of international Formula Student competition, including TU Brno Racing Team. Then there are important rules for the construction of frames and composite monocoques. For the selected production technology are found strength properties of face sheets made of carbon and hybrid fibres. Another part of thesis deals with the design of the sandwich panel using analytical calculation to determine the bending stiffness. On the basis of these proposals are made three-point bending and shear tests. Using of FEM simulation is detected torsional stiffness of the tubular space frame and the monocoque concept from the proposed sandwich panels. The conclusion is devoted to a summary of the important information and possible monocoque manufacturing process.
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Tail units design of VUT 100 aircraft made out composite
Berka, Martin ; Cejpek, Jakub (referee) ; Mališ, Michal (advisor)
This Master´s thesis describes the design of composite horizontal tail of VUT 100 aircraft. Load calculation and selection of the critical load cases is performed. Internal structure of stabilizer and right elevator is designed. Construction materials are chosen and the structure of the composite materials is proposed. FEM models of stabilizer and the right elevator are created in MSC Patran system and consequently the strength test of the models for the selected load cases is executed using MSC Nastran software and COMPOST.
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Designe of a control system for powered sailplane SONG
Cejpek, Jakub ; Šplíchal, Jan (referee) ; Mališ, Michal (advisor)
The objective of this work is to adopt and further expand the type design of the SONG motor glider. The study will result in the basic aerodynamic calculation and the design of lateral control system including structural strength inspection of selected parts. Subsequently, the proposal will allow for further calculation to be made (of flight mechanics, wings strength or fuselage and empennage firmness) and for more specific constructional design of individual components of the glider.
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Progressive Failure Analysis of Composite Material using Finite Element Methods
Častulík, Lubomír ; Cejpek, Jakub (referee) ; Mališ, Michal (advisor)
Bachelor thesis deals with possibilities of progressive failure analysis of layered composite plates. Firstly, there is a theoretical introduction to the mechanics of composite materials. Then the thesis deals with types of mechanisms of failure, including failure criteria, which can be used for their mathematical description. After that, there is presented necessary theory to understand an iteration calculation of progressive failure of laminates. Finally an application of gained knowledge to analysis of model sample for pulling test. This analysis was performed using MSC Patran/Nastran softwares.
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