National Repository of Grey Literature 476 records found  1 - 10nextend  jump to record: Search took 0.03 seconds. 
Form finding of shell structures
Musil, Jiří ; Bažant, Zdeněk (referee) ; Vítek,, Jan (referee) ; Stráský, Jiří (advisor)
The theme of this doctoral thesis is the design of concrete shell structures with the focus on finding their optimal shape. The optimal shape of a concrete shell is the shape in which for a given load (usually the dead weight of the structure) no significant bending moments are generated in the shell and the structure is in the so-called membrane state. The inspiration for this thesis is the work of Swiss engineer Heinz Isler, who developed the shapes of shell structures using model tests of appropriately loaded flexible membranes. He developed the shell structure for large spans by inverting the resultant shape, which carried its weight almost entirely via membrane forces. The numerical solution of the above experiments using Midas Civil is presented herein. The basic principles of the method are demonstrated on the example of sagged cable. The numerically found shapes are compared with the analytical solution. A shell is designed based on the numerically found shapes and its stress response to dead load is described, particularly in relation to the membrane action. In the next part, the acquired knowledge and methods were used to design three relatively complicated shell structures. Each structure was statically analysed and its static behaviour was described. Structures with perfectly rigid or flexible supports, which simulate real behaviour of the supports, were studied. In the final phase, the results of static analysis of the selected shell were experimentally verified on a physical model in a scale of 1: 55.56. The model has been built using 3D printing. The thesis describes the use of a modelling similarity, the model design, the production process, and the experiment. The load test confirmed the optimal design of the shell structure and the validity of the numerical method for finding their shapes.
Product Innovation Using CAE and Additive production
Bočková, Pavla ; Videcká, Zdeňka (referee) ; Vyroubal, Petr (advisor)
This bachelor thesis is focused on the design and construction of an innovated shape of the clamping mechanism of the one-handed dumbbell. The clamping mechanism model and other parts of the dumbbell are modelled using the parametric modeler called SolidWorks. The resulting model is printed on the Ultimaker 2+ 3D printer using the Fused Depositionion Modeling method. The thesis also includes the introduction of selected CAx systems, the characteristics of Rapid Prototyping as well as the FDM method and materials used. The end of the thesis is completed by the technical economic evaluation of the production of the proposed prototype of a one-handed dumbbell.
Design of a chess manipulator
Novák, Tomáš ; Parák, Roman (referee) ; Cejpek, Zdeněk (advisor)
The bachelor’s thesis deals with a design and realization of a chess manipulator and its controlling through a graphical user-friendly interface. The theoretical part is divided into two sections, a brief insight into manipulation technique and a more in-depth characteristic of robotic manipulators. The practical part focuses on the chosen chess set and a concept of the robotic manipulator. The following parts then describe the structural units, motor and control units and electronic components. Additionally involves the practical part the design and implementation of the manipulator via the Arduino and the user interface. In the final part is created a functional model and designed possible future improvements and development.
Functional foams with densit ygradient
Svatík, Juraj ; Figalla, Silvestr (referee) ; Jančář, Josef (advisor)
Vycházíme-li z lehčených přírodních materiálů, lze od porézních materiálů s gradientem porozity očekávat mechanické vlastnosti nadřazené konvenčím polymerním pěnám, a to díky jejich specifické architektuře. Tyto vlastnosti umožňují použití lehčených materiálů jako strukturních prvků. V této práci je popsaná příprava gradientních porézních materiálů pomocí laminování a/nebo 3D tisku. Provedeny byly statické a dynamické mechanické testy na obou kvazi homogenních a gradientně porézních pěnách poskytující experimentální podklad pro hypotézu deformační odezvy plynoucí ze strukturní architektury. Data se interpretovala užitím zavedených teoretických modelů. Naše výsledky vedly k závěru, že tyto teoretické modely odvozené od pěn s pravidelnou strukturou není vhodné aplikovat pro pěny s gradientem porozity, protože prokazují podstatně lepší mechanické vlastnosti než homogenně porézní pěny.
Design of mechanical, electrical construction and software equipment of autonomous cell "Soda maker" for Industry 4.0 testbed.
Dvorský, Petr ; Baštán, Ondřej (referee) ; Kaczmarczyk, Václav (advisor)
The objectives of this bachelor thesis are design and realization of an autonomous cell for soda production for the testbed of Industry 4.0. First, basic construction principles of the autonomous cell are outlined. Then, the mechanical design, the hydro pneumatic system design, the electrical design and the software design are described. The drawing of the mechanical construction of the cell was devised using CAD NX 12 (Siemens PLM software). Most of the 3D printed parts were printed on 3D printer Tarantula. Hydro-pneumatic system was designed in SMC PeuDraw 2.8 for maximal working pressure of 8.2 Bar. Electrical documentation was created in electrical CAD software WSCAD. For control and communication, the autonomous cell is equipped with PLC SIMATIC S7-1200 (CPU 1214C DC/DC/DC), HMI panel (SIMATIC HMI KPT400 BASIC) and Linksys SD205 switch. The source code for control PLC and HMI was designed in TIA Portal software.
CoreXY type FDM 3D printer
Kyselica, Martin ; Vyroubal, Petr (referee) ; Jaššo, Kamil (advisor)
The aim of this work is a theoretical evaluation of the properties and differences between the relevant 3D printing methods with a closer focus on FDM. The principles of the basic types of 3D printer mechanisms using this technology are explained in more detail and compared with each other. The solution and parts list of FDM 3D printer with CoreXY mechanism is proposed which is then constructed and tested.
3D printing in popularization of science
Kubíčková, Klára ; Zmrzlá, Petra (referee) ; Langerová, Petra (advisor)
Tato bakalářská práce se zabývá především využitím 3D tisku veřejností, která není s touto technologií seznámena. Práce je rozdělena do dvou hlavních částí – první část uvádí teorii a druhá část předkládá praktické aktivity. V první části je definovaná terminologie spojená s 3D tiskem, je stanoven proces 3D tisku, a je nastíněn historický vývoj procesů 3D tisku. Kromě samotného 3D tisku je v první části této práce popsán i proces tvorby 3D tisknutelného modelu a také jsou popsány možnosti využití 3D tiskáren. Kromě již uvedeného jsou také popsána 3D tisková pera. V druhé části, praktické části, jsou navrženy konkrétní aktivity pro děti s využitím 3D tiskových per nebo 3D modelovacích programů. Veškeré tyto aktivity obsahují očekávanou délku trvání, věkovou skupinu a hlavní cíl.
Heat exchangers
Kuráňová, Helena ; Rubinová, Olga (referee) ; Uher, Pavel (advisor)
The master thesis deals with the issue of heat recovery and efficiency of exchangers. The experimental part is dedicated to the measurment of efficiency of a plastic model of heat exchanger with atypical construction compared to a standard plate heat exchanger. For production of the heat exchangers 3D printer was used so the thesis uses the possibilities that 3D printing is offering nowadays.
Technology of waste polylactide recyclation for 3D print
Kecíková, Alžbeta ; Tocháček, Jiří (referee) ; Přikryl, Radek (advisor)
This bachelor thesis deals with the recycling of waste polylactide from the production process and its subsequent use in 3D printing. To optimize the recycling process of polylactic acid, it was recycled with the addition of various additives such as poly(3-hydroxybutyrate), talc, limestone and chain extenders Joncryl 4368-CS and Raschig Stabilizer 9000. These materials were also investigated with the addition of the acetyl tributyl citrate plasticizer. Samples of the mixtures were prepared on a twin-screw extruder and subsequently a filament was obtained using a single-screw extruder, which was then used for 3D printing by fused deposition modelling (FDM) technology. Temperature towers were printed to obtain optimal processing temperatures for 3D printing. The effect of the additives on the characteristic temperatures and the degree of crystallinity of the PLA was determined by differential scanning calorimetry. The effect of the processing on the molecular chain of selected samples was observed by gel permeation chromatography. Furthermore, in the experimental part of the bachelor thesis, the influence of additives on mechanical properties such as modulus of elasticity, tensile strength and elongation was investigated. The molecular weight was increased due to the chain extenders. Of the particle fillers for the PLA matrix, talc had better mechanical properties than limestone. The greatest effect of the plasticizer was in a mixture with poly(3-hydroxybutyrate).
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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