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Influence of dynamic loading on the contact fatigue characteristics of bearing material
Hložek, Jiří ; Hutař, Pavel (referee) ; Mazal, Pavel (advisor)
This thesis deals with the study of sudden step changes observed in model testing of standard bearing steel 100Cr6. Methodology of experiments with step change of load is proposed and applied in measurements. Three complete series of experiments were conducted, and rating life was determined for each loading trend. Based on the experiments carried out, it was found that the selected steel is able to withstand the sudden step of load changes, despite the fact that it is not material of choise for this type of load. Part of this work was to verify functionality of the innovated test stations AXMAT with modern diagnostics and a new control system, and also of the hydraulic variant of AXMAT, which allows to remotely derive dynamic loading of the test sample.
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Twin-disc machine for the study of wheel-rail wear and rolling contact fatigue
Šperlich, Vilém ; Skurka, Šimon (referee) ; Galas, Radovan (advisor)
Presented thesis describes the design of an experimental device used for the study of wear and contact fatigue of wheel-rail contact. The text describes selected devices already used for the study of wheel-rail contact. The main part of the text focuses on choosing a suitable conceptual variant and the design of the resulting twin-disc machine with linear contact. The final design enables easy mounting of the specimens and their precise positioning. The final part of the text contains calculation of estimated price of this device.
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Testing of the Common-rail pressure regulation valve by ADwin device
Šoulák, Vojtěch ; Svída, David (referee) ; Kučera, Pavel (advisor)
Tato diplomová práce se zabývá rozšířením testovacích možností vývojové stanice pomocí zařízení ADwin. Hlavní částí diplomové práce je navržení přídavného okruhu testovací stanice a naprogramování testu pro tlakový regulační ventil. V další část se diplomová práce zabývá předpokladem stavu komponent regulačního ventilu po testování. Při porovnání tohoto předpokládaného stavu a reálném stavu po testování je ověřeno správné naprogramování testu a správná funkce nově navrženého okruhu.
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Influence of dynamic loading on the contact fatigue characteristics of bearing material
Hložek, Jiří ; Hutař, Pavel (referee) ; Mazal, Pavel (advisor)
This thesis deals with the study of sudden step changes observed in model testing of standard bearing steel 100Cr6. Methodology of experiments with step change of load is proposed and applied in measurements. Three complete series of experiments were conducted, and rating life was determined for each loading trend. Based on the experiments carried out, it was found that the selected steel is able to withstand the sudden step of load changes, despite the fact that it is not material of choise for this type of load. Part of this work was to verify functionality of the innovated test stations AXMAT with modern diagnostics and a new control system, and also of the hydraulic variant of AXMAT, which allows to remotely derive dynamic loading of the test sample.
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Adaptation of shock absorbers testing device on contact fatigue testing of dynamically loaded surfaces
Nepovím, Lukáš ; Čípek, Pavel (referee) ; Dvořáček, Jiří (advisor)
This bachelor’s thesis deals with the design of an adapter for the modification of a test device, where the automatic tensioners (dampers) of automotive belts are tested. The proposed adapter allows to test the functionality of the valve tappet assembly. The design of a simple test methodology is also a part of the solution. The first part of the thesis deals with the overview of the given issue. Subsequently, the design variants of the adapter and the loading methodology of the tested component are proposed. The main part describes the design of the adapter, the method of lubrication of the tested component, the measuring equipment used in the experimental test and the design of the test methodology. The complete drawing documentation of the adapter is the output of this work.
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Development of a testing system for evaluation of rolling bearings with variable lubrication parameters
Škoviera, Jozef ; Čermák, Jan (referee) ; Omasta, Milan (advisor)
The presented diploma thesis deals with the design of a test system for rolling bearings, which allows the change of the lubrication parameters (e.g. changing of the relubrica-tion interval). In the document, the reader first learns about the meaning of lubrication of rolling bearings, the possibilities of lubricant supply to the bearing (specifically for the supply of grease) and the possibilities of dosing control. Subsequently in the document is described the present state of experimental stations for testing rolling bearings, which is available at the Institute of Machine and Industrial Design. The end of the part about current state of knowledge is also mentioned the possibility of speeding up fatigue tests. In the next part, the author describes his own solution. The result is the design of an experimental station (for option to relubricate with grease), the creation of a lubrication control platform and the creation of a basic program. Part of the work is also verification experiments and drawing documentation.
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Design of the computational lifetime prediction methodology for the roll bearing
Vaculka, Miroslav ; Vlk, Miloš (referee) ; Vrbka, Jan (advisor)
This master’s thesis deals with a fatigue analysis of a roller bearing. The fatigue analysis consists of determining service-life of a roller bearing using a stress-strain analysis with finite element method and subsequent numeric calculation using software fe-safe with application of Brown-Miller multiaxial fatigue criterion. Service-life of a roller bearing is determined by number of cycles to failure in the form of pitting formation which is consequence of contact fatigue. According to calculations was found an inappropriateness of Brown-Miller criterion for high-cycle contact fatigue. Test of other available criteria was performed. Principal-Strain criterion provided the best match with ISO 281 standard.
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Development of a New Generation of Devices with Advanced Diagnostics for Determining Contact Degradation
Dvořáček, Jiří ; Hájek, Karel (referee) ; Náhlík, Luboš (referee) ; Pazdera, Luboš (referee) ; Mazal, Pavel (advisor)
The thesis proposes a methodology for damage identification of thrust bearings using acoustic emission method. The work is the way of the hydraulic loading of specimens and thrust bearings with programmable settings severity and duration of load cycles during contact fatigue tests at stations Axmat. They are designed structural adjustment elements (waveguides) to capture the acoustic emission signal selected apparatus, including the modification of software to capture the data. At the described experiments is verified functionality of the circular test specimens and axial bearings . Part of this work is to propose a new methodology for identifying early stages of contact fatigue using a combination of diagnostic methods.
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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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Influence of topography of rubbing surfaces on rolling contact fatigue
Zahradník, Radek ; Čermák, Jan (referee) ; Vrbka, Martin (advisor)
This master thesis deals with influence of topography of friction surfaces on rolling contact fatigue. This influence is examined by newly reconstructed R-MAT station, whose reconstruction and fully report about it, is part of this master thesis. Influence is examined on area with higher surface's roughness which it wasn't examined before. Further research is made on area of surfaces with topographical modification with higher surface's roughness.
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