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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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Design of modern speaker body with usage of new technology
Kůst, Martin ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This diploma thesis deals with the analysis and design optimization of a speaker cabinet (enclosure) produced by the additive technology of 3D sand printing. The introductory part is devoted to the theory, both in the field of noise, vibration and the method of their calculations, as well as the theory of speakers and their systems. Numerical and experimental modal analysis is performed, which were compared to determine the mechanical properties of the new material, including material damping. This is followed by experimental and numerical harmonic analysis, with output in the form of a numerical model describing the behaviour of the structure during its excitation. The data are compared with a modal analysis of the internal acoustic space and the critical shapes and their frequencies are determined. At the end of the work, construction modifications are proposed to increase the rigidity of enclosures, the influence of which is evaluated on the created numerical models.
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Dynamic analysis of structure loaded seismic loads
Janošková, Lenka ; Nevařil, Aleš (referee) ; Vlk, Zbyněk (advisor)
In this diploma thesis the seismic load on two different models is solved – the first model is a beam hall and the second model is a multistory building. The calculation of seismic load was performed according to standard ČSN EN 1998-1 (Eurocode 8) using the response spectrum analysis and the method of equivalent static forces (substi-tute load). For the combination of seismic responses in different directions are used SRSS and CQC rules. Models and calculations were solved in a student’s version of program RFEM 4.10 (Ing. Software Dlubal, s.r.o.). The comparison of mentioned methods in each models, also the comparison of combinative rules in calculation and the final evaluation of seismic responses on both of models are the subject of this thesis.
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Modal analysis of vocal folds models with descrete parameters
Lekeš, Filip ; Švancara, Pavel (referee) ; Hájek, Petr (advisor)
Bachelor’s thesis deals with modal analysis of computed models of human vocal folds. It’s about finite element and analytical model where values first eigenfrequencies come under male vocal folds. Research part applies to biomechanics of vocal the human voice, which is followed by an overview of computational models. Finite element model is completely created and solved by ANSYS Workbench commercial program, which uses the finite element method to simulate a problem. Solution of analytical model uses freely available Python programming language. Analysis of the results and comparison of approaches belong to main objectives of the presented work. The proposed analytical model can serve future students for detailed understanding of human vocal oscillations.
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Design of cable-stayed pedestrian bridge
Uher, Lukáš ; Kulhavý,, Tomáš (referee) ; Nečas, Radim (advisor)
This diploma thesis aims to design a structure of pedestrian bridge over the Svratka river. To make a preliminary study of possible bridging, three different outlines were drafted. The cable-stayed variant was selected for further analysis. Two towers, inclined in both their longitudinal and transverse direction, support a cast-in-place post-tensioned concrete deck through stay cables anchored in the tower and the deck. After determining the desired initial state, a finite element analysis was carried out using the Ansys software. The capacity of all main load-bearing elements was checked so it meets the ULS and SLS design criteria in accordance with EN 1992 codes.
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Analysis of railway motor-generator set
Mánek, Petr ; Hadaš, Zdeněk (referee) ; Ondrůšek, Čestmír (advisor)
This work is focused on using of modal analysis in power electrical engineering. The first part of the work explains the term of CAD systems and provides their basic classification. The next section of this thesis describes procedure for creating models in Autodesk Inventor 2012. There is shown creation sketching, 3D components, assemblies and possibility of presenting the models. Next part of this thesis describes the finite element method and the program ANSYS Workbench. In the next part of this thesis is shown sample of calculation of modal analysis in the program ANSYS Workbench. There is a description of modal analysis, synchronous machines, the process of calculating of modal analysis and evaluation of the results. The last section of this thesis describes creation of animation of the railway generator set in the program Inventor Studio.
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Design of the ROPS protective frame
Zimek, Rostislav ; Machálek, Jakub (referee) ; Pokorný, Přemysl (advisor)
This thesis deals with the design of the protective frame protecting occupants in rollover (ROPS). The creation of the calculation model, in order to perform a stress-strain analysis of the frame under the conditions of the homologation test. Execution modal analysis with the inclusion of the mass of the auxiliary device. A motion for a protective frame is designed so that it can be subjected to destructive test according to standards ČSN EN ISO 3471. The strength and modal analysis was carried out using the finite element method (FEM). The diploma thesis was conducted in cooperation with the company, the Tatra Truck a.s.
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