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Calculation of storage tank structure for sewage treatment plant
Pečenka, Lukáš ; Maňas, Pavel (referee) ; Prokeš, František (advisor)
This diploma thesis is focused on finite element analysis of storage tank. The designed computational model in this work is based on existing storage tank documentation. Diploma thesis is divided into parts. Introduction part consists of various storage tanks types description and basis of finite element method. Next part contains methodical process of computational model designs, its characteristics and purpose. Designed models are loaded with set of specific border conditions. These tests are evaluated and described more closely. After that, the table of results is created and von Misses stress of all models is compared. The best model matching real construction is selected after this compare. The final part of this work consists of suggested construction changes based on the analysis results.
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Replica of a historical machine gun mount
Doležal, Jakub ; Suchý, Jan (referee) ; Maňas, Pavel (advisor)
This bachelor's thesis deals with the analysis and construction of the Královopolská gun mount replica, which were equipped in selected objects of Czechoslovak border fortifications before the World War II. This work is devoted to the analysis of the original documents for the gun mount, CAD model creation, 3D scanning and modification of scanned polygonal mesh of the heavy machine gun vz.24, which was selected as an example of machine guns mounted in the Královopolská gun mount. This is followed by a virtual compatibility check of the gun mount model with the machine gun model. The production model creation is introduced in next part, using technology with the lowest possible production costs. Complete drawing documentation for the replica production is also part of this bachelor thesis.
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Numerical model of lattice structure under dynamic loading made by Selective Laser Melting technology
Červinek, Ondřej ; Maňas, Pavel (referee) ; Vrána, Radek (advisor)
For the purpose of mechanical impact energy absorption in the transport industry are mainly used special profile absorbers. For highly specialized applications is required to use components that are designed for specific kind of deformation. Example of these parts are industrial-made metal foams or micro-lattice structures produced by SLM technology. This paper focuses on low-velocity dynamic loading prediction of BCC micro-lattice structure made of aluminum alloy AlSi10Mg by SLM technology (SLM 280HL). For this purpose dynamic FEM simulaton of the micro-lattice structure was developed, supplemented by model of BCC structure material obtained from mechanical testing. Real geometry of tested samples obtained from optical measurement (Atos Triple Scan III) was further implemented in the numerical model. Dynamic BCC structure load experiment was performed on a drop-weight tester. Behavior of structured material in drop-weight test was described by the course of deformation and reaction forces over time. Comparable results were obtained for flat loading of dynamic FEM simulation and experiment. Inclusion of production phenomena in simulation led to increased accuracy and compliance with experiment. Tool for testing the effect of geometry change on mechanical properties was created. To achieve more accurate results with puncture load, it is necessary to modify the material model with real material deformation at test sample failure.
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Development of sabot component via finite element method and 3D metal printing
Hajda, Jan ; Maňas, Pavel (referee) ; Paloušek, David (advisor)
This thesis deals with the development of the missile carrier also known as sabot, which is weight optimized considering the manufacturability using 3D metal printing. Therefore, a numerical model containing all the influencing parameters based on which topological optimization was performed was compiled in the solution. This was followed by the production of sabot and its evaluation with the help of optical digitization and computer tomography. We managed to achieve 29% weight savings on sabot, which led to an increase in the kinetic energy of the missile by 4.9%. Using the results obtained, it was found that part of the armor-piercing ammunition can currently be produced using 3D printing. This fact may affect the future design of the missile, or the possibility of the production of missiles, where it would be possible to produce a missile on the battlefield.
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Topology optimisation using lattice structures
Černák, Martin ; Maňas, Pavel (referee) ; Vaverka, Ondřej (advisor)
This thesis aimed to develop and verify the methodology for lattice topology optimization, which deals with additive manufacturing specifications and is independent of the optimization solver. The developed methodology uses the SIMP topology optimization algorithm. The penalization factor used for a solution is based on the mechanical properties characterizing arbitrarily chosen unit cell. These are identified using the homogenization method applied to the real geometry specified by 3D optical digitization. Verification is based on FEA using the variable homogenized properties. The local stress response is simulated by submodeling technique. The methodology was verified by optimizing the braking shield bracket of a plane. The optimized part is 22 % lighter and 31 % stiffer than the original solution. Results of the thesis demonstrate that the proposed methodology is suitable for structural part optimization and allows us to use lattice structures together with topology optimization and additive manufacturing relatively easily, not only in the space industry.
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Design of lattice structures for additive manufacturing using Selective Laser Melting technology
Vrána, Radek ; Maňas, Pavel (referee) ; Koutný, Daniel (advisor)
Metal additive technology allows to create objects with complex shape that are very difficult to produce by conventional technologies. An example of such component is a porous structure which is composed of periodical truss cells. This diploma thesis deals with the prediction of the mechanical properties of very small lattice structures made of additive manufacturing technology Selective Laser Melting. Using the proposed test specimens it was found that real dimensions of the trusses varies with size and orientation to the base platform. It was proposed and tested samples for rod tensile test made of SLM. Based on the real information about dimensions and mechanical properties of rods were predicted mechanical properties of lattice structures. A lot of mechanical tests were carried out to obtain the real mechanical properties. Test results and conclusions are described in the thesis.
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Design of mountain-bike crossbar and its FEM analysis
Jelínek, Martin ; Maňas, Pavel (referee) ; Vrbka, Martin (advisor)
The aim of this diploma thesis is the part of evolution of the new bicycle frame for mountain biking, category enduro. The first part of this thesis is focused on creating dimensional modified model of the bike frame in CAD system SolidWorks. Subsequently this frame will be detailed by FEM analysis in software ANSYS Workbench and determine boundary conditions for this analysis. The final part is about visualization of the new bike frame.
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Computational modelling of strain and stress in spur gearing using FEM
Ševčík, Martin ; Maňas, Pavel (referee) ; Vrbka, Martin (advisor)
This diploma thesis deals with computation modeling of spur gearing using FEM. The methodology of checking calculation was suggested for gears which are not possible to check only by using standard ČSN 01 4686. The analysis of influence of vicinity of stress concentration on stress distribution in tooth root was performed. It is possibility to use the gears with thinner rim than the standard ČSN 01 4686 recommends. The main part of this work is devoted to fatigue crack propagation study in gears with thin rim. Aiding T-stress the influence of constraint and stress multiaxiality on crack propagation was taking into account. The predicted fatigue crack propagation paths were compared with certain experimental data. It is demonstrated that the considering of influence of constraint improves estimation of consequent crack propagation direction and in some cases the influence of constraint can significantly change the estimated crack propagation path.
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Study of behaviour of EHD lubricated contact of machine parts within non-smooth surfaces
Zapletal, Lukáš ; Maňas, Pavel (referee) ; Vaverka, Michal (advisor)
Master’s thesis deals with development of software application to calculate contact pressure in eleastohydrodynamic lubricated contact in order to use previously obtained data of the lubricating film thickness. The introduction contains a short overview of methods used for the study of film thickness and contact pressure. Custom work includes a contact pressure solution derived from a film thickness, a description of the developed software and analysis of algorithms used for its compilation. The last part deals with the verification of algorithm, application of software for calculating the contact pressure on the rough surface and analysis of the results. The conclusion includes a summary and possible application of software in practice.
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The design of two axis solar tracker
Krejčí, David ; Maňas, Pavel (referee) ; Klapka, Milan (advisor)
The purpose of this dissertation is to design the dual-axis solar tracker carrying the concentrator photovoltaic panels. The preamble of the dissertation shortly examines a photovoltaic cells development up to concentrators and the common support structures of solar power plants. The second part focuses on the engineering process itself. It includes the choice of the variant that suits best the requirements, the calculations of wind load and design of the various joints. The conclusion part is devoted to the evaluation, economy analysis of the construction and proposals for improvements.
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