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Design of Stationary Machine for Threadig Plastic Sheathing on Wide Bandsaw Blades
Riedl, Jan ; Vespalec, Arnošt (referee) ; Koutný, Daniel (advisor)
This thesis deals with the design of a machine for threading plastic sheathing on single-sided band saw blades with dimensions from 4500 x 80 x 1.0 mm to 12500 x 290 x 1.85 mm. The aim of the thesis is to create an assembly model, the text is focused on a detailed description of the machine. The device was designed in SOLIDWORKS software. The main goal and partial goals of the thesis were met. The thesis is developed to the level of structural design and assembly description, along with calculations of key parts in the structural solution. The method of operating the machine is outlined. The thesis can serve as a starting point for future designs of a machine for threading protective plastic sheathing on saw bands of the stated dimensions.
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3D Construction Printing of Coarse Aggregate Cementitious Composite
Vespalec, Arnošt ; Czarnecki, Sławomir (referee) ; Lloret-Fritschi, Ena (referee) ; Koutný, Daniel (advisor)
Today, the construction industry experiencing a period of rapid development. This is resulting in a massive production of greenhouse gas emissions (39% of global CO2 production) and an overexploitation of scarce natural resources leading to inevitable climate change. In this context, cement binders production represents one of the most significant environmental challenges. Despite extensive research being conducted on alternatives to cement, there remains considerable untapped potential in conventional building materials. The situation has led to a paradigm shift in the conventional construction sector, as inventive manufacturing techniques, including automation, are implemented. This predominantly involves additive manufacturing, particularly 3D printing in the construction industry, commonly referred to as 3DCP (3D Construction/ Concrete Print). The dissertation examines the possibilities of using a mixture with coarse aggregate for 3DCP technology. This mixture has the potential to increase production efficiency and reduce the amount of other components, decreasing Portland cement usage and as a result, CO2. The thesis investigates a workability of a mixture containing 8 mm coarse aggregate and its effect on the printing parameters. Finding the optimal combination of process parameters for a mixture using simulation tools can improve its buildability, eliminate the need for a trial-and-error approach and thus rapidly reduce waste. Analysis of the results demonstrates that the mixture containing coarse aggregate exhibits less buildability than the mixture without coarse aggregate. Although the mix containing coarse aggregate exhibited a lower level of rigidity in comparison to the mix without coarse aggregate, the Young's modulus values obtained are similar to those reported in other research dealing with printable "concrete" at early mixture ages. Further investigation using Design of Experiment (DOE) techniques resulted in a combination of 3D printing process parameters (print footprint dimensions, print speed) that were validated by the simulation software Abaqus. The utilisation of these process parameters has resulted in enhanced print stability, thereby improving the buildability of the printed object, and reducing the occurrence of deformation. The mixture containing coarse aggregate effectively diminishes the requirement for additional mix material components by around 16%, resulting in decreased cement consumption and substantial CO2 emissions (equivalent to 52 kg per cubic metre of concrete). These factors, in conjunction with 3D printing technology in the construction industry, contribute to a sustainable approach to industrial production. This research contributes to a greater comprehension of the behaviour of cementitious composites with coarse aggregate sizes of up to 8 mm and their dependence on printing parameters. The findings and outcomes are summarised in three peer-reviewed scientific articles.
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Comparison of tensile properties of polymeric samples produced by extrusion based 3D printing
Krajcar, Ivo ; Vespalec, Arnošt (referee) ; Škaroupka, David (advisor)
The subject of this work is a summary of the contemporary knowledge about 3D printing and mechanical properties of a prototype manufactured this way. Main goal is to compare the frequently used FDM method with the innovative APF method of 3D printing from the Arburg company. ASA and CPE materials were chosen for researching this method. On these materials, tensile strength was measured. Aditionally, for comparison between the two methods, referential samples manufactured by injection moulding were made. A percentual difference in strength of each sample was compared against these. 60 samples in total were made for this comparison. After evaluation of the results, it was found that in the tensile strength the samples made by the APF method are approximately 30 % less strong than the referential sample. The samples made by the FDM method are approximately of the same strength as the referential sample.
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3D printing quality evaluation using optical digitization
Schäffer, Matúš ; Vespalec, Arnošt (referee) ; Paloušek, David (advisor)
This thesis focuses on description of selected differences in printing strategy and functionality of proprietary and commercial slicer. These are tested by specially created experiments using the same FDM table printer and filament. 3D optic digitisation is employed to support accurate measuring of individual experiments. Then 3D scans are examined in inspection software which allows to attain the figures describing dimension and geometry accuracy. Subsequently, the results are analysed and the conclusion is defined.
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Design of the autonomous snow groomer
Vespalec, Arnošt ; Surman, Martin (referee) ; Škaroupka, David (advisor)
The subject of this master’s thesis is the design of an autonomous snow groomer intended for the treatment of well-geodetically mapped slopes of ski resorts. Designed design uses an innovative approach to detecting the thickness of a snow cover by an electromagnetic sensor system. The work identifies and presents the concept of solving specific problems of autonomous operation in ski areas, in the form of a design vision. This concept is presented and verified using a parametric model.
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Design of single-purpose cutting machine for shortening of plant stems
Žižka, Jakub ; Brandejs, Jan (referee) ; Vespalec, Arnošt (advisor)
This bachelor thesis deals with the design of a single-purpose machine for cutting plant stems. The task of the machine is to cut already partially shortened and stripped wheat straw stalks to the required length. The operation of the machine is fully automated, the operator only ensures the supply of semi-finished products to the machine, removes the finished stalks and controls the operation of the machine. In the thesis is a search describing the existing technologies used for cutting plant stalks, the possibility of driving a single-purpose machine and possible solutions for transporting stalks. The research also includes an analysis of the necessary mechanical and physical properties of wheat stalks. Subsequently, the analysis of information from the research part of the thesis and the definition of important parameters for the design construction balance sheet is performed. In the practical part of the work are developed concepts of possible solutions of individual structural nodes and justification of the choice of individual solutions. The second part of the practical part deals with the construction design of a selected conceptual design, including calculations. The work shows a possible solution for the construction of a machine for processing semi-finished products with a large variety of shapes.
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Advanced filaments for FDM/FFF 3D printing
Kučera, Jan ; Vespalec, Arnošt (referee) ; Koutecký, Tomáš (advisor)
The bachelor thesis deals with the issue of FDM/FFF 3D printing with a focus on rapidly evolving new filaments and their use in industry. The aim of this work is to display a large number of filaments that have been tested and to categorize them into individual groups for future use. Selected tested materials from scientific studies address both the mechanical properties of individual pure filaments and the effect of additives to these filaments. The analysis of these works then showed that the effect of carbon fiber varies according to the type of base material and the weight percentage of filling. From a practical point of view, the results of this work can be used in the choice of material for printing models and prototypes for own usage.
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Design of a paper waste container
Jančová, Petra ; Haltof, Vladimír (referee) ; Vespalec, Arnošt (advisor)
The aim of this work is to create a conceptual design of a paper recycling container with regard to aesthetic shaping, effective use of internal storage space, handling, transport and ergonomic requirements. It solves the shortcomings of current containers by timeless shaping using modern materials and reliable production technologies. The result is a practical container design that uses psychology to encourage the public to sort paper waste and thus contributes to environmental responsibility and sustainability.
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UAV design for civil and commercial purposes
Linhartová, Simona ; Křenek, Ladislav (referee) ; Vespalec, Arnošt (advisor)
The topic of this bachelor thesis is design of an UAV suited for commercial and civil use. The goal is to create a drone with compact looks and user–friendly composition that fulfils ergonomic and technical needs in compliance with professional use. The thesis includes the state of the art in the field, design and technical analysis that shall present the reader to contemporary issues in the field of UAV.
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Modification of printhead for 3D print of concrete
Diakov, Jakub ; Paloušek, David (referee) ; Vespalec, Arnošt (advisor)
This bachelor’s thesis deals with the engineering design of the adjustment of the jet used for continuous 3d printing of the concrete mixtures which are used for the printhead which already exists. The main function of the jet is to shape and deposit the printed mixture in a way that it corresponds to the required geometry of the product. The thesis contains a research focused on the issues of 3D printing such as properties of concrete flow, influence of the shape and size of the end of the jet on printing and individual mechanisms related to the optimal use of these jets. The second part of the thesis contains the analysis of knowledge and the determination of the appropriate parameters for the construction of the jet. These parameters influence the geometry and the quality and effectiveness of production. The practical part of the thesis is focused on the possible structural design of the jet adjustment based on the knowledge from the research part of the thesis. The practical part also deals with the design of the jet in a way the flaws and imperfections occurring in case of the previous constructions of the jets. In case of use of the jet designed in the corresponding way, the production can be substantially accelerated, and the quality of products can be substantially higher.
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