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Hodnocení kvality svaru pomocí nedestruktivních technologií
Jakeš, Jakub
The bachelor's thesis deals with an analysis of individual non-destructive methods that are used in practice to check welds and welded structures. The introductory part discusses the principles of individual welding methods and the problems that may arise during the welding process. In the next chapter, individual methods of non-destructive testing are described, where their origin, principle and accessories for their application and their deployment in practice are specified. Much attention is paid to the acoustic emission method, for which the individual specifications are described in more detail. In the final of thesis, a verification experiment is performed, on which the functionality of the acoustic emission is demonstrated.
Use of acoustic emission technology to assess corrosion of materials
Procházka, Adam ; Vašíková, Simona (referee) ; Binar, Tomáš (advisor)
The thesis deals with the description of acoustic emission as a non-destructive testing method and its use in the detection of material corrosion. The first part describes the theoretical principles dealing with the explanation of what acoustic emission is, how it is defined according to the standard, what are the types of acoustic emission and how it is tested. It then discusses corrosion, the types of corrosive environments where corrosion occurs and the types of corrosion tests. It also describes where acoustic emission has been used in practice and what experiments it has been used for in terms of material monitoring. The next part of the paper describes the experiment of acoustic emission measurement on grey cast iron samples, describes the fabrication of the samples, the use of corrosion protectors, and the placement of the samples in a condensation chamber for continuous testing. The last part is the evaluation of the results .
Granulometry by the acoustic emission method
Pokorný, Tomáš ; Šedivá, Soňa (referee) ; Fialka, Jiří (advisor)
This paper compares influence of different waveguides and acoustic emission sensors on particle sizing analysis using acoustic emission. Several experiments are proposed, executed and evaluated to find the impact of waveguide length and diameter in combination with resonance or broadband sensor.
Analýza průběhu spalování akustickým signálem
Procházka, Jan
The presented diploma thesis monitors and evaluates the combustion process in conventional internal combustion engines according to the measurable and observable parameters, such as acoustic signal specifically. The first part of thesis focuses on the classification and use of internal combustion engines. Moreover, the combustion of the mixtures in cylinders is described as well as individual components of the engine that monitor and measure the combustion process. In the next part, the issue of acoustic emission is specifically addressed followed by the analysis of the combustion process using th acoustic signal. In conclusion, the use of the acoustic signal as an analytical tool for the evaluation of the combustion process is assessed according to the obtained results.
Hodnocení kvality pomocí nedestruktivních technologií
Šarocký, Robert
This diploma thesis is focused on evaluating quality of materials which are manufactured by additive method of production. The thesis describes methods of additive production and their materials. Furthermore, the thesis deals with the methodology of investigation of mechanical properties of products of additive production. The following part of the thesis describes production of samples from two different types of material. Subsequently, these samples were tested by acoustic emission in the impact bending test and the tensile strength test.
Diagnostics of rotating parts mounting systems in a wind turbine nacelle
Krontorád, Jakub ; Vlašic, František (referee) ; Mazal, Pavel (advisor)
The core aspect of thesis is management of work and diagnostics of wind turbines. It contains an overview of wind energy in Czech Republic and collects a relevant information from international papers and studies regarding the topic of diagnostics and maintenance of main mechanical components located in nacelle of wind turbine. It contains a recommendation for improvement of working conditions of wind turbines and their maintenance, which would lead to decrease of failure rates of the wind turbines main mechanical systems due to the utilization of acoustic emission and high frequency vibrations monitoring. Experimental part of the thesis contains analysis of acoustic emission signal from anonymous wind turbine with maximum energy output of 2000kW in Czech Republic to illustrate the sensitivity of acoustic emission and introduce its principles.
Evaluation of cold kinetic deposition technology (Cold Spray)
Buček, Tomáš ; Zimáková, Jana (referee) ; Binar, Tomáš (advisor)
Cold spray or Cold gas dynamic spraying is actually new process for coating application. Origin of Colds technology spray is thermal spray. Cold spray technology has some advantages therefor any other common thermal technology. Cold spray technology has unique properties mainly due to low deposition temperatures and the physical principle of layer growth. Master’s thesis has focused on the possibility of use for corrosion protection. Accelerated corrosion tests were performed in a condensation chamber with samples of aluminium substrate and low pressure cold sprayed copper layer. The formation of corrosion was evaluated by acoustic emission and metallographic analysis. The anti-corrosion properties of copper have been considered in practical design, as have the unique antibacterial and virus inactivating properties.
Evaluation of the use of non-destructive methods of acoustic emission on materials
Vašíková, Simona ; Zimáková, Jana (referee) ; Binar, Tomáš (advisor)
This master thesis is about acoustic emission itself and acoustic emission as a nondestructive method of testing materials. There are different types of metal materials corrosion too. In this thesis is possible also find corrosion protective methods. There are practical examples of use the acoustic emission method at metal materials corrosion from automotive, aviation, food processing and manufacturing industry with construction and civil engineering examples. The experimental part is focused on samples preparing and measuring the acoustic emission signals during continual corrosion process of grey cast iron in condensational corrosion chamber. These results are supported and completed with metallographic analysis.
Studium nestabilní plastické deformace metodou akustické emise
Molnárová, Orsolya ; Dobroň, Patrik (advisor) ; Lukáč, Pavel (referee)
The influence of the strain rate and heat treatment on the occurrence of plastic instabilities in extruded AlSi1MgMn (6082) and cold rolled AlMg4.5Mn0.4 (5182) alloys was studied. The samples were uniaxially loaded at various strain rates and at room temperature (RT). The results are discussed using concurrent acoustic emission (AE) monitoring during mechanical testing and the AE parameters are correlated to the microstructure and to the stress-time curves. All samples exhibited the Portevin-Le Châtelier (PLC) effect of different types, dependently on the heat treatment and the applied strain rate. The occurrence of the PLC effect is manifested by burst AE signals with high amplitudes. Statistical analysis of the AE signals has shown the power-law probability distribution.
Investigation of basic deformation mechanisms of magnesium alloys by means of advanced in-situ methods and theoretical modeling
Čapek, Jan ; Mathis, Kristián (advisor) ; Landa, Michal (referee) ; Šiška, Filip (referee)
The work is focused on developing testing methods for investigating of the deformation mechanisms of magnesium alloys. The work involves the measurement of in-situ acoustic emission and neutron diffraction and comparison to the theoretical models. Mg + 1wt.% Zr alloy was selected for investigation of the compression - tension asymmetry. Advanced analysis of acoustic emission and neutron diffraction data revealed activation of different slip systems during deformation. Moreover, the different evolution of twinning was explained. The same methods were used to investigate the aluminum influence on deformation mechanisms. The hardening of basal slip and twinning and increasing importance of prismatic slip was observed.

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