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The machining of electrical insulation materials
Svoboda, Marek ; Prokop, Jaroslav (referee) ; Osička, Karel (advisor)
This work aims to provide an analysis and definitions of problems during the machining of electrical insulation composite materials. The main objective of this work is to put forward innovative alternatives in order to deal with technological conditions. The chosen alternative is then subjected to both testing and economic evaluation.
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Design of Wing and Landing gear for TST 14 MC Glider
Štěpánek, Jan ; Šošovička, Róbert (referee) ; Juračka, Jaroslav (advisor)
Modification of TST-14 MC glider, calculation of flight envelope, distribution of lift on the wing, calculation of loading cases of the wing, strength check of choosen construction nodes, design of the landing gear retraction mechanism, setting up loading of landing gear according to ULKM, strength check of landing gear
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Fracture Toughness of Composite with Al-matrix and Carbon Fibres
Michalička, Jan ; Klement, Josef (referee) ; Molliková, Eva (advisor)
Abstract The objective of this study was a values evaluation of fracture toughness of fiber-metal laminates (FML) compounded from carbon fibers in epoxy matrix and aluminium plates of lay-up 6/5. Samples with unidirectional and bidirectional orientation were tested experimentally. In the case of unidirectionally oriented samples an effect of moisture absorption to epoxy matrix on the values of fracture toughness was reviewed. A fracture toughness calculation was realized by COD method firstly. A bigger pop-ins in F – COD diagram as critical moments for "delta"c evaluation were considered; it was determined by 5% tangential line. It was found out, that results of this measurement weren’t in agreement with plane deformation condition and for this the results couldn’t be rated as fracture toughness "delta"Ic. A method of J integral for fracture toughness evaluation was used consequently. A test of elastic compliance changes before J integral calculation by all of samples was performed. Beginning of stable grow of crack was determined by this method. A critical forces Fc from beginnings were established, which were used for calculation of Jc. A functional dependence of elastic compliance on crack opening had specific waved shape before its linear (up to exponential) grow. It was observed in all cases. The critical forces Fc from the end of “wave” preceding the continual grow of compliance were determined. Equations stated in standards for J integral calculation were used, which are for metal materials normally used. Despite this was found out all of results of Jc were in good agreement with plane deformation condition and could be rated as fracture toughness JIc. In this study were found out these pieces of knowledge about fracture toughness of FML CARE: Unidirectional CARE had fracture toughness JIc about 76 kJ/m^2 and the same type but with bigger amount of absorbed moisture had JIc about 4 % higher. In this case negative moisture influences on CARE weren’t found. Bidirectional CARE had fracture toughness JIc about 31 kJ/m^2; it was about 65 % less then in the case of unidirectional CARE
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Analysis of varnish composites properties in the course of moisture
Novák, Petr ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
The presented bachelor´s work deals with preparation of micronized mica filled varnish sauples. At the same time the temperature and relative humidity influence on the electrical properties of composite material by dielectric relaxation spectroscopy method are monitoring. The composite material consists of epoxide varnish TSA 220S, which is modified with different mass percentage of micronized mica. The results of this project are frequency dependencies of real and imaginary parts of complex permitivity with the environmental temperatures and humidities parameters of varnish components.
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Study of electric properties of composite
Bariš, Marián ; Havlíček, Svatopluk (referee) ; Polsterová, Helena (advisor)
The theme of this Bachelor's thesis is a problematics of composite materials. On a given samples of polyamide with a various weight filling of a milled mica were measured resistivity, permittivity and loss factor on a consequence of a temperature and filling. The chosen type was a filling with a milled mica in range from 0 to 40 of a weight percentage, temperatures were in range from 20 °C to 90 °C.
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Properties of filled micro- and nanoparticles varnish composites
Novák, Petr ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
The presented work deals with preparation of test samples filled microparticles of mica and nanoparticles of silicon dioxide (SiO2). Monitors the impact of climatic conditions and filler on electrical properties of composite materials. Electrical properties of composite materials are measured by dielectric relaxation spectroscopy. Test samples influence of epoxide resin TSA 220S and polyester resin DOLPHON XL 2102. Varnishes are modified with different weight percentage of nanoparticles of silicon dioxide, or micronized mica. The results of this project are frequency dependencies of parts of complex permittivity and their evaluation.
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Controlled heating of Composite Material
Fajkus, Martin ; Macháň, Ladislav (referee) ; Šteffan, Pavel (advisor)
The supposed thesis considers problem of heating of composite material for outdoor application. Basement of thesis is analysis of submitted sample of composite material. Measured values of composite material were compared and evaluated and than acceptable samples were choosen for next application. Part of thesis is creation of measuring software for analysis of sample. Other part of thesis is realization of equipment of control unit for heating of composite material. Control unit makes it possible to regulate heating and to set up parameters from computer.
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The controlled heating of composites materials
Fajkus, Martin ; Havlíček, Tomáš (referee) ; Šteffan, Pavel (advisor)
Expected work solves problem of controlled heating of composite material for outdoor application. Basement of work is analysis of submitted concrete specimen of composite. Then I find out influence of direct and alternating voltage on submitted specimen and I choose method of measurement. Whereas I chose correct method of measurement, I could measure all specimens. From comparing I chose specimen of composite material, which are suitable for a next application. For chosen specimen of composite material I designed control unit for heating and tempering. The control unit was designed according to their parameter.
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Dielectric Properties of Thermoplastic Materials with Ground Mica
Fiala, Ivo ; Havlíček, Svatopluk (referee) ; Polsterová, Helena (advisor)
The subject of this thesis are composite materials, measuring of their dielectric qualities, particularly of the polyamide and the polyamide filled with various weight percentage of the ground mica. The essential intent of the thesis is to determine the measuring methodology and respective measurement of the basic dielectrical quantities of materials, as are loss factor and the complex permitivity components. The measuring should be done for various temperature and humidity combinations. The thesic contains the physical explanation of measured dependences.
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