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Fatigue evaluation methods for pressure equipment utilising numerical analysis results
Boleloucký, Václav ; Lošák, Pavel (referee) ; Létal, Tomáš (advisor)
Diplomová práce se zabývá hodnocením únavové životnosti v okolí konstručního uzlu tlakové nádoby, kde vzniká výrazná koncentrace napětí a je zde předpoklad primárního vlivu na únavu materiálu. Konkrétně se jedná o místo přechodu kontrolního otvoru do pláště analyzovaného zařízení. Práce obsahuje teoretickou a praktickou část. V teoretické části jsou představeny pojmy a metody hodnocení, související s danou problematikou. Na základě těchto metod je provedena analýza konstrukčního uzlu tlakové nádoby. Analýza je provedena metodou konečných prvků na skořepinovém a objemovém modelu nádoby v softwaru ANSYS Workbench, její výsledky dále zpracovány a vyhodnoceny dle aktuálního návrhu úpravy evropské harmonizované normy EN 13445--3, kapitoly 18. Výsledky analýz jsou hodnoceny v závěru práce.
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Structure and fatigue properties of selected titanium alloy
Prudíková, Alena ; Kohout, Jan (referee) ; Věchet, Stanislav (advisor)
Main topic of the thesis was to evaluate fatigue properties of the titanium alloy Ti-A13-V2,5, labelled by ASTM as Grade 9. Most attention was focused on fatigue behaviour of the alloy in the range of high cycle fatigue. Fatigue testing was realised to detect the fatigue properties and consequently to generate the Wöhler curve and the Haigh diagram. In addition to this, tension and bending tests were performed. Metallographic and fractographic analyses of fatigue fracture form part of the overview about material properties, which was accomplished by use of REM. Experimental part of the thesis was backed by the literature research. The first half of it contains a short summary of basic information about the titanium and its alloys, so as some chapters about the history and properties of titanium, the way of its production, classification of titanium alloys and its thermic treatment. The fatigue is thoroughly scrutinised in the second half of the background research. Here can also be found the information about the fatigue process, its stages, the fatigue life and the most significant attributes of the fatigue fracture. The last chapters of the thesis are dedicated to the alloy Ti-A13-V2,5 - being examined in the experimental part - so as to its fatigue properties. The main benefit of this thesis is the completion of the missing information concerning the fatigue behaviour of the alloy, which is – according to the literature research - generally not available.
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Influence of thermal shocks on fatigue of pressure equipment components
Umlauf, Martin ; Vincour, Dušan (referee) ; Létal, Tomáš (advisor)
This thesis examines influence of thermal shock on fatigue of pressure equipment components. The paper relates to project of IMI CCI Brno, which is a leading manufacturer of valves for the energy and process industries. Analysis concerns the impact of thermal shock concentrating on high pressure part of the steam valve. And proposal for a new valve geometry that reduces machining operations and reduce financial costs of production. First part of the thesis presents a basic review of fatigue damage components concerning mechanical loading and thermal – mechanical loading. Second part of the study creates FEM model of the valve. FEM model simulate temperature field and stress during thermal shock. Influence of thermal shock to fatigue damage was computed on basis of stress tensor obtained from FEM simulation under Chapter 18 of the standard EN 13445-3. Existing valve geometry was verified and the new geometry was proposed that simplified and reduce financial costs of production.
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High Cycle Fatigue Modelling in ANSYS Workbench
Zoubek, Vojtěch ; Řehák, Kamil (referee) ; Dlugoš, Jozef (advisor)
This diploma thesis deals with the extension of the solution of high-cycle material fatigue in Ansys program. The goal of the thesis is creation own algorithm for evaluation of FEA results and overcoming the existing built-in tool. Thesis is divided into theoretical and practical part. In theoretical part, there was created literary research about material fatigue and current solution options. Practical part introduces own algorithm of evaluation.
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Low cycle fatigue research and application in nuclear industry
Sehnal, Dominik ; Kuželka, Jiří (referee) ; Hůlka, Jiří (advisor)
Fatique life extension of nuclear powerplants lies in the search for project reserves. This work deals with the evaluation of low-cycle fatigue of nuclear installations of the VVER type and the assessment of the influence of the computational model level. Fatigue tests of austenitic steel using optical method of digital image correlation for which the evaluation procedure is designed and used is performed. Selected model of plasticity with kimenatic (Chaboche) and combinated hardening (Chaboche, Voce) are calibrated from the obtained data. Subsequently, the durability of the test specimen is determined by computational modeling for different material models. From the comparison of the results of fatigue tests with the calculation, the material models suitable for the description of fatigue life and their validity are determined.
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Comparison of fatigue fracture criteria for uniaxial tension
Stolář, Jakub ; Šebek, František (referee) ; Horníková, Jana (advisor)
Bachelor’s thesis „Comparison of fatigue fracture criteria for uniaxial tension“ is focused on material fatigue and the possibilities of material service life aproximation for uniaxial tension. Research study of material fatigue and fatigue fracture criteria is stated in the first part of the thesis. In the second part, experimentally measured data are processed and application suitability of particular fatigue fracture criteria is assessed while using the research study theoretic findings.
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Advance evaluation of fatigue resistance of selected construction materials
Benešová, Anna ; Květoň, Josef (referee) ; Seitl, Stanislav (advisor)
This thesis deals with the analysis of S–N curves of models according to Basquin, Kohout and Věchet and Castilla–Canteli using Weibull and Gumbel solution. These curves are interpolated by measured data of cyclically loaded civil engineering materials like concrete and steel. For each material, the accuracies of individual models are determined and in the conclusion, the suitability or unsuitability of individual models for selected materials is compared and evaluated.
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Destruktivní metody testování materiálu
Veverka, Vilém
The submitted bachelor's thesis deals with destructive methods of material testing with a focus on tensile testing and material fatigue. The aim of the bachelor's thesis was to prepare an overview of individual destructive methods of material testing and comparison of tensile diagrams of samples. In the bachelor's thesis, 3 types of samples were investigated, which were printed on a Prusa i3 MK3s 3D printer from ABS, PLA and PETG materials. Test specimens were modeled in Fusion 360 according to ASTM D638. The tensile test was performed on a ZDM 5/51 universal tensile machine according to the ASTM D638 standard. The results show that the sample made of PLA material has the highest tensile strength of 41,23 MPa.
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