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Development of WAAM process parameters for thin-walled components made of magnesium alloy AZ61
Šváb, Čeněk ; Němeček, Stanislav (referee) ; Slavíček, Jakub (advisor)
The thesis deals with the development of WAAM (Wire Arc Additive Manufacturing) process parameters for thin-walled parts made of magnesium alloy AZ61. The aim of the thesis is to find suitable process parameters and describe their influences on the welding process. To achieve this goal, these parameters were experimentally tested. It was found that the parameter of boost phase current and the duration of its application have the highest influence on the weld geometry. The stability of the welding process was then influenced by the electrode feed rate during the boost and burn phases. Based on these results, a final set of parameters was created, which successfully welded a thin-walled part composed of 50 layers and reaching a height of 130 mm.
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Additive manufacturing of spatial trusses from polymeric materials
Křivohlavý, Petr ; Němeček, Stanislav (referee) ; Škaroupka, David (advisor)
This thesis is focused on creating polymer lattice struts without any necessary support in full length using robotic 3D printing. The aim of the thesis is to find suitable process parameters and printing strategies with respect to the accuracy of the polymer struts. A statistical model of effects of individual process parameters has been produced to achieve stated objectives. The model enables finding optimal process parameters. The printing strategies for thus established process parameters are tested to increase the accuracy of the finished print and the quality of the bonds between individual struts. The accuracy assessment is executed using optical 3D metrology. The maximum deviation from the nominal shape 0.54mm has been accomplished using discovered process parameters and printing strategies.
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System of large-scale 3D printing of products from bar structures
Vašátko, Marek ; Němeček, Stanislav (referee) ; Škaroupka, David (advisor)
This thesis deals with the design of a system for the production of lattice spatial structures from polymer materials printed by a robotic arm. The aim of the thesis is to design a suitable manufacturing system in general and to experimentally verify the production of products on the current form of the system. Using compression tests to determine the load carrying capacity of the fabricated lattice structures and compare it with a computational model of the ideal geometry. In general, the parts of the manufacturing system were designed and experimental measurements of compression tests on fabricated specimen structures were carried out. The first results of compression tests of such fabricated structures for two cell topologies were obtained. The accuracy between the experiments and the computational model is comparable to the results in the current literature. Better results were obtained in the areas of repeatability of the obtained load values. The system is a combination of HW and SW solutions providing 3D printing of large-scale lattice structures for large volume parts and represents an incremental improvement of partial properties.
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Design of recoating system for processing of two metal powders using 3D Printing
Guráň, Radoslav ; Němeček, Stanislav (referee) ; Koutný, Daniel (advisor)
The thesis deals with the design, construction and testing of two different metal powder coating equipment, which is able to work with SLM 280HL metal 3D printer. Since the field of multimaterial metal printing by selective laser melting (SLM) has not been significantly investigated yet, an overview of existing patents and possible approaches to the solution has been developed. The device has been successfully designed and a series of tests was carried out defining the issue of applying an improved head that uses a nozzle and an eccentric vibration motor. Based on the experiments performed, the coating parameters of the multimaterial layer of FeAm and 316L materials were defined. A control system for the partial process automation was created for the proposed device. The device was implemented in a printer that demonstrated both the ability to apply a single multimaterial layer of at least 50 m thickness, and the ability to produce a 3D multimaterial component comprised of up to 200 layers and containing material change across all axes.
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Mechanical design of 3D printing head for concrete mixtures
Slavíček, Jakub ; Němeček, Stanislav (referee) ; Paloušek, David (advisor)
This diploma thesis deals with a design and manufacture of an active print head used for 3D printing of concrete mixtures. The aim is to ensure functional parameters of the print head at a minimal mass. Extrusion of the material from the print head is ensured by a screw conveyor, shaping of the material is carry out by a rotatably mounted nozzle provided with trowels. The dimensioning of the main elements of the print head is based on the parameters measured during tests with the older version of the print head and on the FEM analysis. The print head was manufactured and is able to extrude concrete mixture with an admixture of aggregate (fraction 4–8 mm) at a rate of 0,5–2 m3•h-1. The weight of the print head is 16.4 kg, which is 30 percent less than an older print head weighed. The manufactured print head was tested during the printing of a real object and met all the required parameters. The print head is ready for implementation in a machine providing large-scale printing of parts in the construction industry.
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Development of WAAM process parameters for thin-walled components made of magnesium alloy AZ61
Šváb, Čeněk ; Němeček, Stanislav (referee) ; Slavíček, Jakub (advisor)
The thesis deals with the development of WAAM (Wire Arc Additive Manufacturing) process parameters for thin-walled parts made of magnesium alloy AZ61. The aim of the thesis is to find suitable process parameters and describe their influences on the welding process. To achieve this goal, these parameters were experimentally tested. It was found that the parameter of boost phase current and the duration of its application have the highest influence on the weld geometry. The stability of the welding process was then influenced by the electrode feed rate during the boost and burn phases. Based on these results, a final set of parameters was created, which successfully welded a thin-walled part composed of 50 layers and reaching a height of 130 mm.
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System of large-scale 3D printing of products from bar structures
Vašátko, Marek ; Němeček, Stanislav (referee) ; Škaroupka, David (advisor)
This thesis deals with the design of a system for the production of lattice spatial structures from polymer materials printed by a robotic arm. The aim of the thesis is to design a suitable manufacturing system in general and to experimentally verify the production of products on the current form of the system. Using compression tests to determine the load carrying capacity of the fabricated lattice structures and compare it with a computational model of the ideal geometry. In general, the parts of the manufacturing system were designed and experimental measurements of compression tests on fabricated specimen structures were carried out. The first results of compression tests of such fabricated structures for two cell topologies were obtained. The accuracy between the experiments and the computational model is comparable to the results in the current literature. Better results were obtained in the areas of repeatability of the obtained load values. The system is a combination of HW and SW solutions providing 3D printing of large-scale lattice structures for large volume parts and represents an incremental improvement of partial properties.
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Time resolution of TileCal and searches for heavy metastable particles
Pagáčová, Martina ; Leitner, Rupert (advisor) ; Němeček, Stanislav (referee)
Title: Time resolution of TileCal and searches for heavy metastable parti- cles Author: Martina Pagáčová Department: Institute of Particle and Nuclear Physics Supervisor: Doc. RNDr. Rupert Leitner, DrSc. Supervisor's e-mail address: Rupert.Leitner@cern.ch Abstract: In the present work, the timing of the ATLAS TileCal is stud- ied using the single hadron collision data. The time resolution and also the mean time response depend on the energy deposited in a given cell. The results are compared to the previous analysis with jets and muons. Precise time-of-flight measurement using TileCal can be used to identify the heavy long-lived particles predicted by the models of physics beyond the standard model. Their mass can be reconstructed by combining with the momentum measurement in the ATLAS inner detector. Finally, the mass resolution of an exotic particle with mass M = 600 GeV is estimated. Keywords: ATLAS experiment, TileCal, time resolution, stable massive particles
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Proton-Proton Interactions at the ATLAS Experiment at the LHC Accelerator
Přibyl, Lukáš ; Němeček, Stanislav (advisor) ; Soustružník, Karel (referee) ; Kupčo, Alexander (referee)
In this thesis the potential of the ATLAS detector to exclude or discover quark compositeness is studied in detail. There were four dierent sensitive analysis methods developed for this purpose. These methods use a detailed information about inclusive dijet pT-spectrum or dijet angular distribution and two of them use Bayesian technique (as is usual in similar analyses at Tevatron). For all four methods a larger number of systematic errors was taken into account and their inuence was studied in detail too. It is also shown, that the early data exclusion limit on quark compositeness reachable by the ATLAS experiment is + LL = 10.3 TeV at 95% C.L with 100 pb 1 of collision data of a sucient quality. This limit is considerably higher than the current limit known from Tevatron: + LL = 2.7 TeV at 95% C.L. The highest exclusion limit on quark compositeness with expected total amount of data to be collected by the ATLAS experiment is above 22 TeV, assuming 3% jet energy scale uncertainty.
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Mechanical design of 3D printing head for concrete mixtures
Slavíček, Jakub ; Němeček, Stanislav (referee) ; Paloušek, David (advisor)
This diploma thesis deals with a design and manufacture of an active print head used for 3D printing of concrete mixtures. The aim is to ensure functional parameters of the print head at a minimal mass. Extrusion of the material from the print head is ensured by a screw conveyor, shaping of the material is carry out by a rotatably mounted nozzle provided with trowels. The dimensioning of the main elements of the print head is based on the parameters measured during tests with the older version of the print head and on the FEM analysis. The print head was manufactured and is able to extrude concrete mixture with an admixture of aggregate (fraction 4–8 mm) at a rate of 0,5–2 m3•h-1. The weight of the print head is 16.4 kg, which is 30 percent less than an older print head weighed. The manufactured print head was tested during the printing of a real object and met all the required parameters. The print head is ready for implementation in a machine providing large-scale printing of parts in the construction industry.
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