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Correlation of AE Signal Changes to Rolling Contact Damage Propagation
Nohál, Libor ; Čermák, Jan (referee) ; Hájek, Karel (referee) ; Hutař, Pavel (referee) ; Mazal, Pavel (advisor)
This PhD thesis deals with the experimental study of more precise rolling contact fatigue damage detection using acoustic emission method. A series of experiments was carried out on two representatives bearing steels and the analysis of sensitivity for the presence of contact damage was performed on selected parameters of acoustic emission. The extent of damage was classified into four classes and signal parameters the most characterizing the development of damage were correlated with the extent of damage. It was also verified the influence of lubricants on acoustic emission signals. The results have an impact on the implementation of more precise rolling contact fatigue tests and evaluation of parameters of acoustic emission signal. On the basis of experiments was established methodology for more precise RCF testing method using acoustic emission on test-rig AXMAT II.
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Design of microscope positioning
Donabauer, Petr ; Mazal, Pavel (referee) ; Čudek, Vladimír (advisor)
This Bachelor thesis deals with design and realization of the industrial modular microscope positioning stand in two axis vertical at each other for providing vertical drop of units at measurement. In term of survey of present state are proposed possible solutions followed by selection of the most optimal one and then its construction process. Design documentation is part of this work.
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Raking equipment of sedimentation tank
Šebela, Michal ; Mazal, Pavel (referee) ; Brandejs, Jan (advisor)
Bachelor's thesis contains summary of systems for raking equipment of sedimentation tank. It deals with a specific design solution raking device installed in sewage treatment plant in Ostrava. The goal of this thesis is design suitable solution of raking device. Thesis also contains drawing documentation.
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Design and verification of station for calibration of AE sensors for bearing testing
Bančák, Matej ; Mazůrek, Ivan (referee) ; Mazal, Pavel (advisor)
The diploma thesis deals with calibration of AE sensors used in diagnostics of bearings. Two different conceptual solutions similar to those used in the diagnostics of bearings were designed in the design. Subsequently, the experimental device was designed for relative calibration using the rotation of bearings as a continuous AE source. The experimental part is oriented to the observation of the RMS parameter, which serves as a sensor sensitivity evaluation parameter. As sources of AE, bearings with a certain type of damage were used, which allowed for the formation of sensitivity characteristics according to the type of damage. Sensitivity characteristics of selected AE sensors have been developed to determine the effectiveness in relative calibration. The exponential sensitivity sensitivity of the MDK-13 sensors was observed on the software amplification of the AE analyzer. A proposal for the calibration method for MDK-13 type sensors was developed on the principle of comparison with the reference sensor.
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Alternative energy supplies for garden and week-end house
Novák, Michal ; Mazal, Pavel (referee) ; Venclík, Jiří (advisor)
This bachelor’s thesis contains abstract of alternative energy supplies for garde nand week-end house and describes their advantages and disadvantages. The selected alternative energy supplies are: water-power, solar energy and wind energy. Final part of bachelor’s thesis discuss with a construction machinery for wind energy useage and describes parts of machinery.
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APPLICATION OF ACOUSTIC EMISSION METHOD FOR MORE DETAILED DIAGNOSTICS OF RADIAL BEARINGS DAMAGE
Hort, Filip ; Pazdera, Luboš (referee) ; Hájek, Karel (referee) ; Samek,, Jiří (referee) ; Mazal, Pavel (advisor)
This thesis studies the possibilities of exploiting the acoustic emission method as a tool for more detailed identification of the radial bearings damage formation. The work includes comparison of different evaluation methods in laboratory tests. Applied couplant between the contact sensor areas and sensing surfaces is also taken into account. The practical part includes the presentation of the experimental station and structural adjustments made. The main part of the work comprises the examples in detail of three types of experimental tests that simulate the possible failure of bearings and their manifestation in the sensing signal. Testing methodology developed with recommended values for setting common AE signal measurement, vibration and temperature is a part of the thesis, too.
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Suspended bicycle carrier for buses
Svoboda, Pavel ; Vlašic, František (referee) ; Mazal, Pavel (advisor)
This bachelor´s thesis describes the construction of universal the rack for bicycles to different types of buses. The aim was to produce a simple, lightweight, safe, affordable, accessible design of the rack for bicycles with easy the suspension, but also with the access to the engine compartment of the bus.
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Acoustic emission signal classification at cyclic loading of parts
Stein, Pavel ; Mazůrek, Ivan (referee) ; Mazal, Pavel (advisor)
This master’s thesis is concerned analysis of signal of acoustic emission. The analysis is based on data of bearing material and real bearings testing, tested in the Axmat stands. The data was run by software Matlab and Python. Below I created plan for identification of damage stage depending on particular AE events. The results are put into diagram. Finally I’m trying to develop the new possibilities of using acoustic emission into practice on the real machines. There could be earlier prediction of a defect of monitored bearings compared to vibrating diagnostic used until now.
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Design of the feeding mechanism for L profiles
Witos, Anton ; Vlašic, František (referee) ; Mazal, Pavel (advisor)
In this bachelor thesis was designed machine for feeding L profiles and end effector of service robot. Machine uses pneumatic piston to create frictional force between profile and feeding wheels. For movement of profile is used chain transmission which drive feeding wheels. End effector uses for work special type of electromagnet which uses electric voltage only for disabling. Thesis includes review of suggested solutions and choice of optimal solutions.
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