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Effect of layer thickness on critical angle of additively manufactured lattice structures
Nosek, Jakub ; Vrána, Radek (referee) ; Vaverka, Ondřej (advisor)
Aim of this work is to describe the effect of a layer thickness on critical angel of a lattice structures manufactured by SLM technology. The effect of layer thickness was investigated on single struts and on lattice structures made from stainless steel 316L. Better geometrical accuracy could be obtained, if the smaller layer thickness is used. Less attached powder particles on downskins was also observed on lattice structures. Thanks to this thesis, it is possible to determine, if it is meaningful to decrease the layer thickness in order to improve manufacturability of lattice structures even with higher manufacturing time.
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Design of topologically optimized upright for pneumobil race car
Mende, Milan ; Červinek, Ondřej (referee) ; Vaverka, Ondřej (advisor)
This thesis deals with the design of lightweight front uprights of pneumobile Javelin using topology optimization, followed by manufacturing by additive technology Selective Laser Melting. Aluminium alloy AlSi10Mg was used. Topology optimized parts should have met the requirement of minimal safety factor equal to 2, therefore the stress strain analysis was performed using FEM. The maximal deformation was determined and the safety factor obtained. Two unsymmetrical uprights were designed due to parameters of the brake system. The precision of manufacturing was verified by optical digitization. Machined uprights were mounted on the pneumobile and tested directly on the vehicle. No limit states were observed during testing and subsequent races, so they proved to be fully functional. Weight of the left upright was reduced from 1 609 g to 758 g, the right one was lightened to 741 g.
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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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Heat treatment of maraging steel processted by SLM
Valenta, Jakub ; Vaverka, Ondřej (referee) ; Koutný, Daniel (advisor)
The bachelor thesis deals with the study of the heat treatment of the maraging steel 1.2709 (DIN X3NiCoMoTi18-9-5). The first part of the work is survay of studies that focus on heat treatment of maraging steel made by forging or Selective laser melting technology. Based on that section, a heat treatment was designed by which the samples manufactured on ProX 300 from company 3D Systems and M2 Cusing from company Concept Laser were treated. The effect of heat treatment on the mechanical properties of the samples was subsequently tested by tensile testing and metallographic analysis. The test results of both sets of samples were compared with each other and with the results of other studies and the impact of the described heat treatment on the material was evaluated.
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Crane blocks
Musil, Adam ; Vaverka, Ondřej (referee) ; Brandejs, Jan (advisor)
This thesis is focused on the design of crane blocks for a bridge crane of maximum load of 65 tons. It includes design proposal of the rope, pulley, pulley axle and bearings. Furthermore it contains strength calculations of aforementioned. Last chapter provides assembly drawing, production drawing and bill of material.
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Design of rocker for mountain bike shock absorber using topology optimization
Zalibera, Tomáš ; Hurník, Jakub (referee) ; Vaverka, Ondřej (advisor)
Submitted bachelor thesis deals with research and comparison of topology optimization software. A given component is 3D scanned, after that, kinematics model is done to define possible load cases. Then, topology optimization is done in four selected software. Results from topology optimization are then validated in FE analysis to acquire maximum deformation and stress. After the FEA the best variant is chosen, which is additionally modified to reach sufficient level of safety factor. The discussion and conclusion chapter deals about final comparison of topology optimization software based on FEA resuls and the most suitable software is choosen, in which decrease of deformation by 27% was achieved with a level of weight a bit lower as with the original rockers.
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Optimization of axle carier for formula student for SLM fabrication
Vaverka, Ondřej ; Růžička, Bronislav (referee) ; Koutný, Daniel (advisor)
This diploma thesis deals with design of axle carrier for Formula Student. The axle carrier is topologically optimized and additively manufactured with Selective Laser Melting technology. Material for its production is aluminium alloy AlSi10Mg, which has worse mechanical properties than commonly used high-strength alloys. Therefore the aim was, by using topology optimization, to design a component, which would have comparable properties with milled component. The stress strain analysis was carried out by the finite element method and maximum deformation and safety coef-ficients were acquired. The prototype was made and its dimensions were controlled by optical digitization, which proved accuracy of manufacturing. The strength calcu-lations were verified by special testing device and photogrammetry measurement. The load during the tests was 20 % higher than in the analysis and no limit state was observed. This verified its safety and functionality.
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Historical development of cryptography during the World Wars era
Vaverka, Ondřej ; Ivánek, Jiří (advisor) ; Souček, Martin (referee)
This bachelor thesis deals with the description of cryptographic and cryptanalytic methods during the First and Second World Wars and related historical circumstances. The introduction briefly describes the development of cryptology prior to WWI. The first major chapter examines the application of cryptology during WWI. The next chapter concisely bridges the interwar period, and then focuses on WWII cryptology. The Ultra programme and the problem of Enigma machine is analyzed here in detail. The final chapter is a dedicated to the aftermath of WWII cryptographic efforts in the form of papers by Claude E. Shannon.
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Design of storage containers for powdered metal materials
Vaverka, Ondřej ; Koukal, Ondřej (referee) ; Koutný, Daniel (advisor)
This bachelor’s thesis deals with design of storage container for powdered metal materials used in 3D printer. It contains a short overview of possibilities in metal powders storage, SLM workplace’s requirements and analysis of this problem. Based on this, the goals are specified. The work deals with various solutions and their assessments. In the last part the final version is described, including neccessary calculations and drawings.
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Technicko-ekonomická analýza hydrostatických axiálních převodníků.
Vaverka, Ondřej
This thesis focuses on developing a general summary and description of the function of the hydrostatic drives used in modern agricultural harvesting technology. The following is a list of practical application of the hydrostatic drives on the machine at the same time giving a description of the function of the system. The third part is an evaluation of the measurement of the five hydraulic pumps hydrostatic ground drive combine CLAAS Lexion 560. The hydraulic pumps are classified according to the operating hours, the graph is plotted Q-p characteristics of the pumps and in the end is compared to the wear depending on the operating time. The last part of the thesis deals with the analysis of damage of the hydraulic pump drive combine harvester and determining the cost to repair the drive according to the selected type of repair.
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