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Design of manufacturing technology of a composite part using out of autoclave prepregs
Tellinger, Adam ; Gregor, Lukáš (referee) ; Kupčák, Radim (advisor)
This master’s thesis deals with the production of a composite part from prepregs using non-autoclave technology. The first part of the thesis is research of composite materials and composite manufacturing technologies. This is followed by a section that focuses on non-autoclave methods of manufacturing composite parts using prepregs. The practical part includes the design of several prototype production variants of the specified part and subsequent production of the part. The output is an evaluation of the achieved results, a comparison of the various production methods, the selection of a suitable production technology variant, and the creation of a technological guideline for this chosen method of composite part manufacturing.
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Methodology design and proper measurement setting evaluation of ultrasound testing of composite propellers
Běhal, Antonín ; Horák, Marek (referee) ; Katrňák, Tomáš (advisor)
This thesis focuses on non-destructive ultrasonic testing of composite aircraft propellers. The theoretical part contains a review of manufacturing technologies of laminate propellers and their design. The practical part of the thesis contains the design of ultrasonic testing methodology. Dolphicam 2+ device is used for testing. The creation of appropriate settings of the ultrasonic device, for different laminate thicknesses, is performed on calibration samples containing artificially created defects. By comparing the default and modified settings, it was found that the use of the modified settings greatly improves the distinguishability of the defects from the defect-free laminate. Confirmation of the functionality of the modified setup is performed using a real propeller test. The work serves as a sample procedure for testing a laminate propeller by ultrasonic defect detection.
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Sandwich Insert Design of the Formula Student Monocoque
Velfl, Tomáš ; Šplíchal, Jan (referee) ; Löffelmann, František (advisor)
The bachelor thesis is devoted to the insert joints and wheel suspension attachments on the racing frame of a Formula Student vehicle. First, research was done to obtain the necessary knowledge on the subject. Then the external loads stressing the joints were experimentally and computationally determined. Before starting the actual design of the attachments, the effect of introducing local loads into the sandwich structure of the monocoque was investigated, firstly on small calibration samples. The first phase of testing was to verify the failure mechanisms, the interaction between the different components of the composite sandwich and to test different attachment designs using different materials. Based on the data obtained, the material libraries were refined, and computational models were developed and extended by parametrization. Thus, in the next step, the final designs of the individual suspension points meeting the predetermined objectives were iteratively created. During validation tests, the functionality of the design and sufficient oversizing were demonstrated. Technologies such as CT scanning were also used. The results were evaluated to determine further testing options and further improvements to the current solution.
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Design of repair material with reduced electrical impedance
Žáková, Karolina ; Černý, Vít (referee) ; Drochytka, Rostislav (advisor)
This bachelor's thesis focuses on designing a new composition of corrective material based on silicate with the aim of reducing electrical impedance. In the theoretical part, fundamental concepts necessary for understanding the topic will be described, such as terms related to conductivity, silicates, composites, and corrective materials in general. The experimental section includes the selection of raw materials, preparation, and testing of various compositions of corrective materials with different fillers. The impact of various additives on the electrical properties of the corrective material will be investigated, including its conductivity, resistivity, and cohesion. The final section summarizes and evaluates the achieved results.
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Biocomposites based on polyhydroxybutyrate for 3D printing
Horálek, Matyáš ; Tocháček, Jiří (referee) ; Přikryl, Radek (advisor)
The submitted diploma thesis deals with preparation and characterization of biocomposite based on poly-3-hydroxybutyrate. Biocomposites were fabricated with respect to later use in 3D printing. The methodology for testing different kinds of materials and their suitability for 3D printing as well as evaluation of mechanical and thermal properties was established. The first part of this work was focused on the experiments with print temperature and the material flow rate and its influence on the look of 3D printed object and on the material tendency to warp during 3D printing. The design of the experiment method was used for the analyzing of obtained data. It was proven that the amount of kaolin and tributyl citrate has positive influence in reducing warping. By optimization of the biocomposite recipe it was achieved improvement in tensile modulus of elasticticity, ductility, tensile strength, notched and unnotched toughness.
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Modern Materials for Automotive Industry
Vaníček, Jan ; Fojtášek, Jan (referee) ; Hejtmánek, Petr (advisor)
This work is focused on the description of conventional and unconventional materials that are used to build a car. Individual types of materials are sorted according to their application and characterized in terms of properties and real use. The end of each chapter is devoted to possible future trends.
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Mechanical response of glass fiber-reinforced polymer composite
Širjovová, Veronika ; Svěrák, Tomáš (referee) ; Čech, Vladimír (advisor)
The bachelor thesis is concerned with mechanical properties of glass fiber-reinforced polymer composites depending on the surface modification of fibers and the volume fraction of fibers in the composite. The tested samples in a form of composite beams were consisted of polyester matrix reinforced with long glass fibers without surface treatment (unsized) and with commercial sizing. Shear and flexural tests were employed to evaluate adhesion at the fiber-matrix interface. The theoretical part focuses on literary search for composites, their components (matrix, reinforcement, interphase) and methods of testing their mechanical properties. The experimental part describes used materials, procedures and methods. In the result part, an assessment of the influence of the given conditions on the shear and flexural strength of the composite is summarized.
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Mechanical properties of fiber reinforced composites for automotive applications
Bayer, Adam ; Žídek, Jan (referee) ; Jančář, Josef (advisor)
Bachelor’s thesis deals with studying mechanical features of fiber composites. As a matrix was chosen PMMA and as reinforcement was chosen glass fabric. Theoretical part sums up contemporary issues of polymer composites in automotive industry such as their production techniques and methods of impregnation. In experimental part were prepared samples by block polymerization of 30 % solution PMMA in monomer with initiator by 65° Celsius warmth oath, when was fabric directly unfolded in pre-polymer solution. On these samples were executed tensile tests by testing device Zwick and these samples were compared with results of theoreticaly calculated values.
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Surface treatment of a composite part
Bahenský, Štěpán ; Žák, Ladislav (referee) ; Kubíček, Jaroslav (advisor)
This diploma thesis focuses on composite materials and the possibility of their surface treatment with a focus on painting. The aim was to create a layer on the surface of the material that would serve as protection against UV radiation and subsequent degradation. The first theoretical part is devoted to the material composition. In the subsections, the different types of functional components of the composites are presented. Their possible applications as well as their advantages and disadvantages are described. In addition, the theoretical part is supplemented by the types of methods used for the production of composite materials and the subsequent surface preparation in order to improve the adhesion properties of the material to the paint. The second part, which was developed in cooperation with GDP Koral, s. r. o., deals with the chosen type of surface treatment for composite materials produced by the pultrusion method. The UV coating method was chosen, where the wet layer of the varnish is cured by UV radiation. Two sets of samples were created, which differ in both the method of varnish application and the parameters of the curing process. Mechanical tests were then performed on each sample to verify the resulting adhesion capability of the paint system. The practical part also includes the design of possible technologies for the implementation of the surface treatment in the production line. In the third part, a techno-economic evaluation is presented, which focuses on the cost comparison of standard painting and painting with UV varnishes. The final section contains a summary of the findings and an evaluation of the chosen type of coating with respect to the results of mechanical tests and the possibilities of application in a pultrusion production process.
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