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Optimization of aluminium casting process using numerical simulation
Kolařík, Martin ; Lána, Ivo (referee) ; Krutiš, Vladimír (advisor)
The master’s thesis deals with the analysis of casting technology of the selected aluminium casting. It is a casting of a part of CNC milling machine and it is cast by gravity casting into a permanent mold. The defects which are the cause of a high percentage of nonconforming production were analyzed. Furthermore, the master’s thesis includes a complete analysis of filling and solidification of this casting in the ProCast simulation program. Numerical simulation results are verified and improved. Then the causes of problematic casting defects are proven on several calculated variants. Measures are proposed to minimize the tendency to produce castings with defects leading to nonconforming production.
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Utilization of Virtual Reality Technology in Risk Analysis and Safety of Production Machines
Novotný, Tomáš ; Hajduk,, Mikuláš (referee) ; Krutiš, Vladimír (referee) ; Knoflíček, Radek (advisor)
The doctoral thesis introduces a study of possibilities for utilization of virtual reality technology in risk analysis and safety of production machines. The main goal of the thesis is to analyse and examine possible means of integrating visualization and interaction techniques of virtual reality into the risk identification process in the early stage of the production machine life cycle. The proposed work provides a methodological approach to the theoretical implementation of these techniques in the definition of dangerous areas of a machine, identification of sources of possible risks and verification of applied measures built-in in the machine structure. A system approach is used for forming and optimizing the introduced methodological procedures. The solution includes the design of the methodology for effective transfer of 3D design data into immersion virtual reality domain. This enables overcoming existing barriers in exploitation of virtual reality technologies in industrial applications. The next section introduces a procedure of implementation of real tools and equipment in immersion virtual reality domain, including an option for detection of collisions between the real tools and virtual objects. Experimental tests confirm its capability of practical utilization. The impact of the final practical contribution is shown by a decrease in the number of accidents during assembly work, due to its appropriate planning and thanks to training of the personnel on a virtual prototype, carried out already before the manufacturing of the actual machine. The result of the presented doctoral thesis contributes to further qualitative improvement of techniques and methods for preventive increase of safety and reliability of developed machines, particularly of machining centres, which will help increase their competitiveness. The properties of the designed procedures are documented and verified on real industrial cases.
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Numerical simulation of mechanical properties of cast irons
Haluza, Jakub ; Bouška, Ondřej (referee) ; Krutiš, Vladimír (advisor)
Diploma thesis in the first part deals with the production, properties and application of compacted graphite iron. After then calculation model which is used in ProCAST software for the predicting mechanical and structural properties of compacted graphite iron is presented and differences between versions 2010 and 2011 are shown. The last part of the thesis deals with simulation of mechanical and structural properties on the test specimen and real casting, which is poured in Heunisch foundry Ltd. and results of the simulation and measured values are compared.
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Production of aluminum castings using metal inserts in the technology of casting into ceramic shells
Straka, Pavel ; Zemčík, Ladislav (referee) ; Krutiš, Vladimír (advisor)
The thesis is focused on manufacturing of aluminium castings with inserts by the hybrid investment casting technology. Three measures were proposed to avoid shell cracking caused by thermal expansion of insert. It seems that the covering of insert with a wax is the most efective solution, becasue after dewaxing a gap is formed, which allows insert to dilate. The other solution was based on change of molochite sand to quartz, which has a higher thermal expansion. The last mean to prevent the shell from cracking was adjustment of dewaxing cycle from shock to gradual. Ceramic shell was heated from room temperature to 650 °C. This solution did not avoid shell cracking. Then the simulation of shell heating, pouring of metal and the solidification was made. The information obtained by the manufacturing of experimental casting was used to prototype casting of impeller.
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Utilization and the metal chill optimization in production of heavy casting
Rybička, Petr ; Šenberger, Jaroslav (referee) ; Krutiš, Vladimír (advisor)
Grauation Theses is dealing with optimalization of using chills during the manfufacturing procedures of the casts. The first part is giving an overview about the chills itself in foundry industry. The second part is describing the heating procedures in Cast - chill – mould scheme. In the following part the options of calculations to design the chills are described. The practical part is solving the experimental optimalizations of the chills shape in accordance with the hammer ram.
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3D printing methods for foundry applications
Rendek, Andrej ; Pernica, Vítězslav (referee) ; Krutiš, Vladimír (advisor)
The bachelor thesis is focused on the application of 3D printing methods for foundries, specifically for investment casting technology. The paper describes different printing methods and principles which they are based on with a more detailed description of materials containing their properties and in some cases recommended modifications of the casting process. The last part is devoted to price comparison of three selected methods of model printing for investment casting and dilatometry of six materials with evaluation of their coefficients of thermal expansion and glass transition temperatures.
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Application of 3D printing for Lost Foam technology
Kelbl, Michal ; Krutiš, Vladimír (referee) ; Záděra, Antonín (advisor)
This bachelor thesis is focused on application of 3D print by evaporative pattern casting process. The theoretical part includes introduction to evaporative pattern casting process including processes Lost Foam, Full Mould and Replicast®. The practical part is focused on manufacturing of casting using evaporative pattern casting technology with the use of additive technologies for manufacturing of evaporative pattern. Furthermore, are evaluated manufactured castings.
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Influence of sand size of core mixtures on surface quality of cast iron castings
Brůža, František ; Krutiš, Vladimír (referee) ; Záděra, Antonín (advisor)
The diploma project deals with the mechanisms of burn-on casting defects on castings made of spheroidal graphite cast iron. It discusses the elimination of their occurrence in the conditions of the German foundry MAT Ueckermünde by changing the granulometry of the core sand. Subsequently, the thesis deals with the influence of this change on the greensand. Furthermore, the thesis compares three refractory coatings supplied by the foundry. The coatings are compared both by laboratory measurements and by experimental tests during casting in conditions simulating the operation of this foundry. Finally, the individual tests are evaluated, including the effect of the individual measures in the case of their use in MAT Ueckermünde.
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