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Self Adjustable Discharge Valve
Kuruc, Marek ; Maňas, Pavel (referee) ; Technologies,, Jan Jedlička, Emerson Climate (advisor)
This dissertation deals with design of self adjustable discharge valve used in Emerson reciprocating compressors. This work contains research of current state of knowledge, technical analysis of the valve and calculations of basis parameters. Constructional proposal is then presented. Part of the dissertation is manufacturing of prototype and its test. Finally, conclusions for further development are made.
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Design of cleaning unit of central impression cylinder for flexographic printing machine
Falta, Jan ; Maňas, Pavel (referee) ; Černohous, Pavel (advisor)
This master´s thesis is focused on design and manufacturing of prototype of central impression cylinder cleaning unit. This thesis contains explaining of basic principle of flexographic printing and preview of types of flexographic printing presses. There are explained patented cleaning units and main claims of every patented cleaning unit. In the next part of this thesis, there are some conceptual designs, from which was chosen the final design for manufacturing. In the next part of this work, there are detailly described each of the parts of cleaning unit. Prototype of the cleaning unit was manufactured and tested in the SOMA Engineering s.r.o. Lanškroun. Cleaning unit will simplify the work of operators and reduce time, needed to clean the central impression drum in comparison with manually cleaning.
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Design of entrance ramp for handicapped people to city buses
Pospíšil, Luděk ; Maňas, Pavel (referee) ; Dvořáček, Jiří (advisor)
Diploma thesis deals with the design of the automatically controlled ramp for the boarding of physically disabled people in city buses. The initial research section deals with the regulations and directives that must be respected in the design, the issue of wheelchair mobility and the analysis of design considered elements. In the second part the thesis goes to the chosen design solution. The design input parameters are the height of the ramp cassette, the slope of the ramp when boarding and the width of the boarding platform. The platform is extended by a pair of pneumatic cylinders along with a scissor mechanism guided in a linear ball guide. The boarding platform is made of an aluminium honeycomb panel which strength is verified by analytical calculation. At the front edge, the boarding platform is equipped with a pressure-sensitive edge The ramp cassette is made up of a welded frame of steel profiles and subjected to stress strain analysis. The thesis is accompanied by complete drawing documentation.
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Modification of inert atmosphere circuit of 3D printer SLM 280HL
Somora, Jakub ; Maňas, Pavel (referee) ; Koutný, Daniel (advisor)
The diploma thesis deals with the design modification of the circulation circuit of inert atmosphere in the 3D printer SLM 280HL. The aim of the proposed modifications was to increase the efficiency of condensate and flue gas removal and thus increase the quality of the production process. Based on experimental measurements of the velocity field at a height of 12 mm, it was found that in the original configuration of the build chamber, there are sites with reduced flow velocity. The test subsequently confirmed the increased porosity of the samples in the given localities. Subsequently, with the help of CFD simulations, a lower flow distributor was designed, which had the most significant effect on the porosity. Furthermore, an additional outlet and flow deflector were designed, which had the task of streamlining the drainage of condensate and fumes from under the protective glass of the laser. The designed components were manufactured and experimentally verified, which was able to prove the flow improvement and reduce the porosity on the platform. A test was also performed with a magnesium-based material, which proved more efficient removal of condensate and flue gases. The work managed to prove the influence of the flow velocity on the porosity of the component at differences in flow velocities above 0,3 ms^-1.
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Parametric computational model of non-food bulk materials silo
Červený, Vojtěch ; Kvarda, Daniel (referee) ; Maňas, Pavel (advisor)
This bachelor thesis deals with the creation of a parametric computational model of a bulk material silo. The work includes acquaintance with the issue of bulk materials, the theory of calculation of pressure conditions in silo, introduction of the proposed structure, creation of a parametric geometric model in the CAD system and the calculation model in the FEM system. The thesis includes a brief introduction to the software used and the principle of working with the created models.
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Model of geometry of micro-lattice structures for finite element method
Javorský, Dominik ; Maňas, Pavel (referee) ; Červinek, Ondřej (advisor)
The growing availability of additive manufacturing technology, such as SLM, enables the creation of innovative structural designs. An example of these are complex lattice structures which are used because of their excellent mechanical properties relative to weight. One significant challenge lies in production tolerances. These are not crucial for the majority of components. However, when dealing with lattice structures and their thin-walled geometry, manufacturing tolerances lead to substantial deviations in mechanical properties. The process of designing such structures and achieving results comparable to the experiment requires the use of non-standard methods. These methods are time-consuming and costly for obtaining real geometry. The real geometry is then used for numerical simulations based on the FEM principle. This thesis focuses on the impact of geometric imperfections occurring in BCC-type structures made of stainless steel 316L. During the solution, the real geometry was obtained through optical digitization using the ATOS Triple Scan scanner. Dynamic drop-weight tests were also conducted, and the obtained results were used to modify the geometry model in combination with the acquired real geometry. The aim was to minimize the deviation between experimental and numerical simulation results below 5%. The knowledge gained from this process was then applied in simulations investigating the impact of geometric imperfections. Deviations up to 30% were observed in simulations investigating the impact of geometric imperfections. These deviations can be minimized by incorporating the knowledge of real geometry into the design. The results also help determine the diameter range within which including geometric imperfections in the design is irrelevant. Furthermore, a significant impact of the node geometry on the results of numerical simulations was observed. This knowledge brought the values closer to the experimental data. Another important contribution of this work is the simplified geometry model. This model will enable the study of the impact of additional imperfections in a range that was previously unattainable.
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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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Parametric computational model of non-food bulk materials silo
Červený, Vojtěch ; Kvarda, Daniel (referee) ; Maňas, Pavel (advisor)
This bachelor thesis deals with the creation of a parametric computational model of a bulk material silo. The work includes acquaintance with the issue of bulk materials, the theory of calculation of pressure conditions in silo, introduction of the proposed structure, creation of a parametric geometric model in the CAD system and the calculation model in the FEM system. The thesis includes a brief introduction to the software used and the principle of working with the created models.
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Design of mold segment for molding tires manufactured using Selective Laser Melting
Kvaššay, Adrián ; Maňas, Pavel (referee) ; Rapant, Martin (advisor)
This diploma thesis deals with development and design modifications of tire mould segment which will be batch produced by additive technology Selective Laser Melting. Material for its production is maraging steel 1.2709. Lattice structure was used inside the segment construction. The geometry of the lattice cell was chose based on two main factors – eliminating production costs and providing sufficient stiffness. Strength of the segment was calculated by FEM. The functional sample was made and its distortion was analyzed by optical digitalization.
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