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Use of 3D printing in the production of functional prototypes for automotive
Mikulášek, Marek ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This thesis deals with the 3D printing of composite materials. The constant development of this technology has enabled the application of this method for the production of prototypes, but also functional components. The theoretical part deals with the study of composite materials and the principle of production using additive technology. In the practical part, an analysis of the suitability of part processing using the 3D printing method is performed on a specific component and than applicated to the assembly hall located in ŠKODA AUTO a.s.
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Replacing of metal sheets with laminates
Ulrich, Josef ; Němec, Karel (referee) ; Molliková, Eva (advisor)
The aim of the bachelor´s thesis is composite material, specifically fiberglass. In the first part of this thesis fiberglass is described, their composition, chosen production technology and possibility of use. Mechanical properties and its advantages of fibreglass are compared with metal sheets. Fibreglass is described on example of particular component.
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Verification of actual physical-mechanical parameters of composite material
Jablonská, Markéta ; Žítt, Petr (referee) ; Láník, Jaromír (advisor)
Diploma thesis deals with composite materiál and it is dedicated to steel fiber concreat. The thesis focuses on verification of mechanical parameters of the steel fiber concrete. Especially on the compressive (tensile) strength at first cracking and the compressive strength in cracked state. Testing was conducted on concrete different tensile with 30 kg on m3 steel fibers KrampeHarex DE 50/1,0 N. The thesis is divided into theoretical and experimental part.
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Numerical modeling of failure of a particle composite with ceramic matrix
Kosorín, Michal ; Hrstka, Miroslav (referee) ; Majer, Zdeněk (advisor)
Subcritical crack growth in composite materials plays quite an important role in determination of the service life and leads to the defects growth below the fracture toughness. The thesis presents search of the several scientific works dealing with the determination of the crack growth direction in composite materials. The aim of this diploma thesis was to create 2D and 3D finite element models to analyse crack growth in Low Temperature Co-fired Ceramics (LTCC). These models were compared based on the time calculation of the crack propagation under the subcritical growth conditions.
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Special problems of fracture mechanics of singular stress concentrators in composite materials
Krepl, Ondřej ; Materna,, Aleš (referee) ; Seitl,, Stanislav (referee) ; Klusák,, Jan (advisor)
Předkládaná disertace se zabývá obecnými singulárními koncentrátory napětí a to zejména ostrým vrubem neboli V-vrubem, ostrým bi-materiálovým vrubem a ostrou materiálovou inkluzí. V první části práce je stručně nastíněna Kolosovova-Muschelišviliho teorie komplexních potenciálů rovinné pružnosti aplikovaná na problémy lomové mechaniky. Dále je diskutována lineární elastická lomová mechanika trhlin, V-vrubů, bi-materiálových vrubů a bi-materiálových spojů. V rešerši jsou dále zahrnuta kritéria směru iniciace trhliny i její stability a to kritérium maximálního tečného napětí, faktor hustoty deformační energie a sdružené napěťově-energetické kritérium. Následují text uvádí omezení jednoparametrové lomové mechaniky a výhody její multiparametrové formy. Další část představuje metody pro určení nezbytných parametrů pro popsání pole napětí a posuvů v blízkosti obecného singulárního koncentrátoru napětí. Tyto parametry zahrnují vlastní číslo a zobecněný faktor intenzity napětí. Vlastní číslo je určeno jako řešení problému vlastních hodnot zatímco metody pro určení zobecněného faktoru intenzity napětí tvoří Psi-integrál a metoda přeurčitosti. Obě zmiňované metody jsou aplikovány na zde studované obecné singulární koncentrátory napětí a vzájemně porovnány. Kritéria pro vznik trhliny v obecném singulárním koncentrátoru napětí jsou navržena. V rámci numerických příkladů jsou předpovězeny směry iniciace trhliny a podmínky stability pro konkrétní problémy. Kritické síly pro V-vrub jsou předpovězeny pomocí výše zmíněných kritérií a srovnány s experimentálními daty v literatuře. V následující části jsou ukázány metody analýzy multi-materiálového problému. V závěru práce jsou shrnuty způsoby iniciace a šíření trhliny v blízkosti ostré materiálové inkluze.
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Analysis of mechanical properties of composite materials printed by additive 3D printing technology
Mudrák, Michal ; Joska, Zdeněk (referee) ; Sedlák, Josef (advisor)
This thesis deals with the analysis of mechanical properties of composite materials used for 3D printing by Markforged company. The theoretical part is focused on the characterization of composite materials and analysis of mechanical tests. The experimental part deals with the production of test specimens for specific mechanical tests (tensile test, Shore D hardness test and bending test). The test sapples with Onyx base material are individually reinforced with carbon and high-temperature glass fibers (HSHT). There are statistically evaluated selected parameters for individual mechanical tests (tensile strength, elongation, modulus of elasticity, Shore D hardness, bending stress and bending deformation). The thesisis completed by comparing selected parameters of composite materials with overall recommendations for users.
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Evaluation of dynamic damage of composite structure
Štefanovič, Peter ; Jetela, Václav (referee) ; Klement, Josef (advisor)
The first part of the diploma thesis with name „Evaluation of dynamic damage of composite structure“ focuses on designing device for impact experiments and suitable laminate samples made from prepregs. The conditions and problems of impact tests are also demonstrated here. The second part of the thesis deals with non-destructive control of damaged specimens based on thermography. This is mainly the extent of defects in the impaired area and the evaluation of results using the pulse infrared thermography method. Finally, the relative deviation in the crack size comparison between the visual method and thermographic are compared. Consequently, the residual strength of the damaged samples against undamaged specimens are compared using bending tests.
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Dielectric absorption of varnish composites
Reňák, Ladislav ; Frk, Martin (referee) ; Rozsívalová, Zdenka (advisor)
This work deals with issues of electro insulating varnishes and composite materiále within the frame of dielectric changes depending on a change of relative humidity where these varnishes are located. For this purpose had been created variety of a samples of electroinsulating varnish with different percentage of filling with mica. The general aim is acquire information about dielectric changes of examined electro insulating varnishes that are exposed to atmospheric influence.
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Design and analysis of the road bike made from composite material
Dvořáková, Barbora ; Kubík, Petr (referee) ; Šebek, František (advisor)
This diploma thesis is focused on the design and analysis of road bike frame made of composite material. The thesis is divided into two parts. In the first part, there is a research focused on the usage of composite materials in relation to making bike frames. The main emphasis is placed on fiber composites, which are most common in cycling. Manufacturing process and production technology are discussed. The aim of the second part is design and the numerical simulation of frame in relation to stand-ard, which is used for the testing of frames. Rigidity and strength are evaluated. The final frame is obtained from the initial design due to several iterations. In conclusion, results are evaluated and recommendations for future work are given.
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