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Dynamic models of material in metal forming
Kudláčová, Barbora ; Šlais, Miroslav (referee) ; Forejt, Milan (advisor)
The aim of the Diploma Thesis is to discuss the creation of material models for the forming technology in quasi-static and dynamic loading conditions and to practically propose a methodology of modeling the mechanical behavior of the selected material for dynamic load conditions using the Split Hopkinson Tensile Bar Test. The presented work contains an overview and analysis of individual experimental methods with the influence of the strain rate in terms of the extent of their suitability, the analysis of the plastic deformation mechanism, an overview of the mathematical mechanical behavior models for the materials used for technological practice and the evaluation of the mechanical behavior of stainless steel according to ČSN 41 7348 in terms of flat formability incl. evaluation of microstructure, fractographic analysis and evaluation of results from ferromagnetism measurement of steel after dynamic loading.
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Thermomechanical fatigue of austenitic stainless steels
Dobeš, Ondřej ; Petráš, Roman (referee) ; Horník, Vít (advisor)
The aim of this bachelor thesis was to study the influence of termomechanical fatigue with dwells in loading cycles on material response as well as damage mechanism. Austenitic stainless steel Sanicro 25 was subjected to in-phase and out-of-phase thermomechanical fatigue (TMF) loading conditions with different amplitudes of mechanical strain in the temperature range 250 to 700 °C. The mechanism of the damage was investigated by means of scanning electron microscope equipped with focused ion beam (FIB) and electron backscatter diffraction (EBSD). Different mechanisms of the fatigue crack initiation were observed in in-phase and out-of-phase TMF cyclic loading. The effect of the type of loading on the damage mechanism and fatigue life is discussed.
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Thermomechanical fatigue of austenitic stainless steels
Dobeš, Ondřej ; Petráš, Roman (referee) ; Horník, Vít (advisor)
The aim of this bachelor thesis was to study the influence of termomechanical fatigue with dwells in loading cycles on material response as well as damage mechanism. Austenitic stainless steel Sanicro 25 was subjected to in-phase and out-of-phase thermomechanical fatigue (TMF) loading conditions with different amplitudes of mechanical strain in the temperature range 250 to 700 °C. The mechanism of the damage was investigated by means of scanning electron microscope equipped with focused ion beam (FIB) and electron backscatter diffraction (EBSD). Different mechanisms of the fatigue crack initiation were observed in in-phase and out-of-phase TMF cyclic loading. The effect of the type of loading on the damage mechanism and fatigue life is discussed.
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Dynamic models of material in metal forming
Kudláčová, Barbora ; Šlais, Miroslav (referee) ; Forejt, Milan (advisor)
The aim of the Diploma Thesis is to discuss the creation of material models for the forming technology in quasi-static and dynamic loading conditions and to practically propose a methodology of modeling the mechanical behavior of the selected material for dynamic load conditions using the Split Hopkinson Tensile Bar Test. The presented work contains an overview and analysis of individual experimental methods with the influence of the strain rate in terms of the extent of their suitability, the analysis of the plastic deformation mechanism, an overview of the mathematical mechanical behavior models for the materials used for technological practice and the evaluation of the mechanical behavior of stainless steel according to ČSN 41 7348 in terms of flat formability incl. evaluation of microstructure, fractographic analysis and evaluation of results from ferromagnetism measurement of steel after dynamic loading.
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