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Computational modelling of self-excited oscillation during metal cutting
Malý, Pavel ; Hadaš, Zdeněk (referee) ; Švancara, Pavel (advisor)
Diplomová práce se zabývá analýzou produktivity a efektivity řezného procesu frézování. Pro zjištění kritické hloubky třísky byla analyzována reálná frézka. Model frézky byl vytvořen v programu Autodesk Inventor. Analýza řezného procesu probíhala v programu Ansys Workbench. Výsledky byly použity pro sestavení stabilitních diagramů. Po vyhodnocení výsledků byly navrženy dva přístupy pro zefektivnění procesu frézování. Vliv těchto změn na produktivitu řezného procesu byl ověřen porovnáním výsledků s předchozí analýzou.
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Dynamic characteristic of the workpiece in turning
Nádvorník, Vít ; Štetina, Jakub (referee) ; Fiala, Zdeněk (advisor)
The contens of master thesis is theoretical analysis of vibrations during turning and possibillity to eliminate them, measure dynamic compliance and modal paramteters. The goal of experimental part is to determine the effect of material and type of clamping for three shafts at natural frequency, mode shape and dynamic compliance. Using these results we can optimized cutting parameters and to better overcome vibration during machining.
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Virtual model of part of cutting machine in ADAMS
Juriga, Jakub ; Vetiška, Jan (referee) ; Hadaš, Zdeněk (advisor)
In theoretical part, this master´s thesis deals with vibrations in cutting machine and description of creation of self-excited vibrations theory. In practical part, there is problem of chatter in cutting machine solved with using simulation program Adams and computing program MATLAB. Gradually, Multi body system of cutting machine and model of cutting tool with features flexible body are analyzed. At the end all both models were used to create complex model of the cutting machine .
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Vibrations at machining of metals
Fiala, Zdeněk ; Polzer, Aleš (referee) ; Píška, Miroslav (advisor)
The diploma work deals with a mathematical description of vibration and its generation when machining. Moreover, some techniques of modal parameters measurement in the theoretical part are included. The practical part is designed and based on the measured natural frequencies of the machine with specific tool and materials. In conclusion, a lobe diagram stability for semiautomatic lathe SPN 12 CNC and selected machining operation is specified by means of apparatus.
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Machining of long cylinders
Nádvorník, Vít ; Jaroš, Aleš (referee) ; Fiala, Zdeněk (advisor)
The bachelor thesis deals with the machining of long cylinders and production machines used for the machining technology. The main part contains a description of the vibration system of machine-tool-workpiece and analyzes active and passive methods of its elimination. It also deals with the wear of the cutting tool and a description of the parameters which have a direct effect on tool life.
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Active Vibration Damping/Chatter Control of Machine Tool Spindle Units
Škúci, Michal ; Blecha, Petr (referee) ; Březina, Tomáš (advisor)
This bachelor’s thesis describes the issue about machining, causes of spindle chatter and different ways of chatter damping. It evaluates advantages and disadvantages of different ways of damping. There was made and described simple simulation model on which searching simulations was made for purpose of receiving picture of behaviour of model for different parameters. Model of active damping was made too.
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Regenerative chatter in turning
David, Václav ; Jaroš, Aleš (referee) ; Fiala, Zdeněk (advisor)
Regenerative chatter in turning negatively affects the cutting process, the tool live and the machined surface. In this work is a vibration discriebed by using mathematical formulas or terms. There are listed some causes of creation vibration in turning and some basic methods of complete removal or partial reduction. The second part of this work contains examples of measure and analysis in connection with using of modern software.
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The issue of implementation of social networking in business practice
Uhlíř, Michal ; Basl, Josef (advisor) ; Fortinová, Jana (referee)
The aim of this paper is to provide insight into the issue of enterprise social networking (ESN), other collaborative tools , and instruments of social interaction that can facilitate users their individual work tasks as well as contribute to the overall increase in enterprise efficiency. Futhermore, it offer the familiarization with their available functions and features, robustness and simplicity, advantages and disadvantages. It also offers practical guidance for the implementation of enterprise social networks, or other instrument of enterprise social interaction and what to avoid. The entire paper is conceived to three parts that are logically linked. The first part is theoretical, which is discussed fundamental issues what are social networks about. The second part discussed the concept of corporate social networks, the issue of implementation and at the same time this paper shows the major products to the market. The third part is a survey which evaluate the use of social networking in business practice. The paper thus provides a comprehensive
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Primary electron scattering on biological specimen embedding resins at low voltage transmission electron microscope LV EM 5
BÍLÝ, Tomáš
This master thesis deals with researching the structure of embedding resin in the Low-Voltage Transmission Electron Microscope (LV TEM). Further, it focuses on researching the surface morphology by the Atomic Force Microscope (AFM) and by the Scanning Electron Microscope (SEM). The principle of each of the microscopes is explained ? the contrast formation and construction of the LV TEM in particular. In the conclusion the evaluation of the effect of the surface structure of the embedding resin on the image contrast in the LV TEM and the analysis of the minimalization of its effect on the final image is given.
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