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Multi-filament yarns testing for textile-reinforced concrete
Kaděrová, Jana ; Seitl,, Stanislav (referee) ; Vořechovský, Miroslav (advisor)
The scope of the presented master thesis was the experimental study of multi-filament yarns made of AR-glass and used for textile-reinforced concrete. The behavior under the tensile loading was investigated by laboratory tests. A high number of yarn specimens (over 300) of six different lengths (from 1 cm to 74 cm) was tested to obtain statistically significant data which were subsequently corrected and statistically processed. The numerical model of the multi-filament bundle was studied and applied for prediction of the yarn performance and for later results interpretation. The model of n parallel filaments describes the behavior of a bundle with varying parameters representing different sources of disorder of the response and provides the qualitative information about the influence of their randomization on the overall bundle response. The aim of the carried experiment was to validate the model presumptions and to identify the model parameters to fit the real load-displacement curves. Unfortunately, due to unsuccessful correction of measured displacements devalued by additional non-linear contribution of the unstiff experiment device the load-displacement diagrams were not applicable to model parameters identification. The statistical evaluation was carried only for the maximal load values and the effect of the specimen size (length) on its strength was demonstrated. The size effect curve did not exclude the existence of spatial correlation of material mechanical properties modifying the classical statistical Weibull theory.
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Experimental comparison of recycled and non-recycled filament of ABS plastic
Grygar, Filip ; Krčma, Martin (referee) ; Koutecký, Tomáš (advisor)
Plastic waste which arises from 3D print could be recycled. One of the most used materials is ABS with which this degree work deals. During recycling of ABS mechanical qualities rapidly deteriorate which is compensated by adding non-recycled ABS. This degree work dealt with a ratio of 25% of recycled to 75% of non-recycled material which is a ratio not have been tested so far, and most likely represents a boundary ratio when recycling still makes sense. Unfortunately, it was not possible to extrude from a recycled material a filament of high-quality enough which could be used for problem-free print. It was influenced by non-homogeneity of crushed components and the construction of an extruder. For improving the characteristics a more complex extruder would be needed, with a bigger screw diameter or with two screws, and also a cooling system with more zones. Professional grinders with screens would have to be used for improving homogeneity of the material. The melt flow index of the liquid alloy and the testing of the filament itself showed that this way is practicable and such a recycling is realistic.
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Graphic VFD display control using Atmel microprocessors
Hrubý, Michal ; Pust, Radim (referee) ; Hanák, Pavel (advisor)
This thesis discusses VFD displays; the operating principles, construction, applications, types of displayable information, power supply and control. The thesis explains means of communication and control of modern VFD modules with exemples code. The thesis also includes a selection of a particular graphic VFD display in accordance with the given requirements and design of power supply and control circuits on a printed circuit board.
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Experimental comparison of filament produced from recycled and regular PET
Tomčová, Renata ; Vaverka, Ondřej (referee) ; Koutecký, Tomáš (advisor)
This bachelor thesis deals with the experimental comparison of filament made from recycled and common PET. Filament was made from commercial granulate of PET, PET-G and from recycled PET bottles. Sample pieces were printed using FDM technology from these filaments and then the sample pieces were tested using a tensile test. The sample pieces made from recycled PET filament had one third worse tensile strength than the sample pieces made from common PET and PET-G filaments. Thanks to this bachelor thesis it is possible to decide, if it is worthy producing filament from recycled PET bottles even at the cost of reducing the mechanical properties of final products.
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Electrically conductive surfaces for 3D printed structures
Šomšák, Martin ; Mikulášek, Tomáš (referee) ; Láčík, Jaroslav (advisor)
This thesis describes the technical possibilities of coating various 3D printed structures by different coating methods. Different surface structures have been created on two models for two 3D printing technologies. Antennas on FR4 and PLA substrates were simulated. After adjusting the dimensions of the antennas in the simulations and the results obtained from the simulations, two speckle antennas on PLA substrate were created. To form the antennas, the substrate was coated with copper foil and electrically conductive spray. Subsequently, the antennas were measured, and the results were compared with the simulations.
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Electrically conductive surfaces for 3D printed structures
Šomšák, Martin ; Mikulášek, Tomáš (referee) ; Láčík, Jaroslav (advisor)
This thesis describes the technical possibilities of coating various 3D printed structures by different coating methods. Different surface structures have been created on two models for two 3D printing technologies. Antennas on FR4 and PLA substrates were simulated. After adjusting the dimensions of the antennas in the simulations and the results obtained from the simulations, two speckle antennas on PLA substrate were created. To form the antennas, the substrate was coated with copper foil and electrically conductive spray. Subsequently, the antennas were measured, and the results were compared with the simulations.
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Design of Alternative Production of a Part using 3D Printing Technology
Verner, Tomáš ; Zeman, Břetislav (referee) ; Sedlák, Josef (advisor)
This bachelor thesis deals with the design of an alternative production of a part (sprocket cap). The aim of the thesis is to design an alternative production of the part using 3D printing, to simplify and cheapen the production. The theoretical part includes a description of the existing manufacturing technology and the additive technology (FFF) that will be used for printing the part. Another part of the theoretical work is devoted to the description of additive materials and the subsequent selection of a suitable material, which is PETG material. The practical part of the thesis is devoted to the structural redesign of the part for 3D printing technology and subsequent printing and testing. The thesis concludes with a techno-economic evaluation. The part printed using 3D printing technology performs better from a technical and economic point of view than the original part.
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Progresivní materiály v aditivní výrobě
Holan, Aleš
The bachelor thesis focuses on the additive technology of 3D printing. It presents a basic overview of material, individual production processes and prospective trends of utilization. The practial part consists of the process of producing a prototype component, including intial design, software editing and the process of printing. The final part evaluates the materials chosen for the specific prototype and presents the results of a chemical resistence test conduc-ted specifically for the needs of the component.
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3D model Wanklova rotačního motoru pro výuku technických předmětů
BAŠTÝŘ, Jan
The bachelor thesis deals with the technique of 3D printing and materials suitable for its printing is currently widespread. The theoretical part of the work is focused on the history of 3D printers, a description of selected 3D printers and their comparison, and finally contains an overview of selected materials suitable for use in printing 3D models. The practical part deals with the use of 3D printing for the needs of teaching technical subjects. Within this work, a scale model of Wankel's engine is created for use in teaching.
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Zjišťování pevnostních charakteristik výrobků u 3D tisku
ČECH, Jan
This work inquires into the 3D printing by means of FMD technology. There are compared PLA and Pet-G materials. Further, the horizontal and the vertical printing positions are compared. The results are influenced by the height of the layer as well. There are tested higher layer of 0.25mm and lower layer of 0.15mm. The results are acquired by tensile test.
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