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Strain and stress analysis of the car buffer zone under impact loading
Nedělka, Pavel ; Obdržálek, Vít (referee) ; Vrbka, Jan (advisor)
The master thesis deals with a stress-strain analysis of the front crash structure of a race car by using the finite element method. The structure is loaded by an impact loading. This type of analysis belongs to the transient analysis so the explicit formulation of the finite element method is used. The LS-DYNA software was used for calculations. The goal of this thesis is to express the influence of the crash structure to the change of the car's kinetic energy as well as the amount of absorbed energy in case of frontal impact.
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Study of the Chaboche´s plasticity model complexity influence on the stress and deformation at the high pressure vessel
Paraska, Boris ; Obdržálek, Vít (referee) ; Vrbka, Jan (advisor)
The main aim of this thesis is to define material parameters of Chaboche model of plasticity. Adjustment of the parameters has to correspond to the experimental datas. These datas are represented by an uniaxial strain controlled test curve for fewer than two cycles and also by cyclic stress-strain curve. After that, an cyclic tension-compresion test for various parameters of Chaboche´s model of plasticity is simulated in an ANSYS software. Finally, the most suitable configuration of Chaboche´s model of plasticity is used for cylindrical thick-walled body. Cylindrical body represents a simplified model of high-pressure tank of fuel (diesel) – rail in Common Rail system.
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Computational analysis of the steel-composite carrier of the machining center TM 2000
Zbožínek, Martin ; Obdržálek, Vít (referee) ; Vrbka, Jan (advisor)
The main objective of the work was to perform a computational analysis of the hybrid (steel-composite) carrier and compare the results with the original metal carrier. Static analysis, modal analysis and frequency response were solved. Computation was performed for three different relative positions of the carrier. Static stiffness, natural frequencies and dynamic compliance have been calculated. The results were verified by an experiment performed on a scaled-down model of the carrier. Modern software products, namely MSC Patran, MD Nastran, Matlab and ProENGINEER, were used for the calculation.
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Buckling and Postbuckling of Delaminated Composite Plates
Obdržálek, Vít ; Vrbka, Jan (advisor)
Chování laminátových desek namáhaných na tlak či na smyk může být výrazně ovlivněno přítomností delaminací, tedy oblastí, kde je porušena vazba mezi sousedními vrstvami. Cílem této práce je rozšířit znalosti o chování delaminovaných desek, a to především o chování desek s větším počtem delaminací a desek s delaminacemi libovolného tvaru, neboť taková podoba porušení laminátu více odpovídá poškození vznikajícího v důsledku nízkorychlostního dopadu cizího tělesa na laminátovou desku. Disertační práce se skládá ze tří hlavních částí. V první části jsou stručně nastíněny postupy využívané při analýze boulení delaminovaných desek a jsou diskutována omezení těchto analýz. Dále jsou v této části shrnuty hlavní poznatky o boulení delaminovaných desek. V druhé části práce je popsán výpočtový model použitý v rámci disertační práce pro analýzu boulení delaminovaných desek. Schopnost modelu předpovědět chování delaminovaných desek je pak dokumentována na několika ověřovacích úlohách. Třetí část disertační práce se skládá ze tří samostatných studií chování desek s několika delaminacemi eliptického či kruhového tvaru a jedné studie zabývající se možností náhrady obecného tvaru delaminace kruhem či elipsou. Je probírán vliv řady parametrů na chování delaminovaných desek, konkrétně vliv orientace vrstev laminátu a dále vliv počtu, tvaru, orientace a umístění delaminací. Na základě těchto studií jsou pak zformulována doporučení ohledně postupu při posuzování únosnosti delaminovaných konstrukcí.
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Study of the Chaboche´s plasticity model complexity influence on the stress and deformation at the high pressure vessel
Paraska, Boris ; Obdržálek, Vít (referee) ; Vrbka, Jan (advisor)
The main aim of this thesis is to define material parameters of Chaboche model of plasticity. Adjustment of the parameters has to correspond to the experimental datas. These datas are represented by an uniaxial strain controlled test curve for fewer than two cycles and also by cyclic stress-strain curve. After that, an cyclic tension-compresion test for various parameters of Chaboche´s model of plasticity is simulated in an ANSYS software. Finally, the most suitable configuration of Chaboche´s model of plasticity is used for cylindrical thick-walled body. Cylindrical body represents a simplified model of high-pressure tank of fuel (diesel) – rail in Common Rail system.
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Computational analysis of the steel-composite carrier of the machining center TM 2000
Zbožínek, Martin ; Obdržálek, Vít (referee) ; Vrbka, Jan (advisor)
The main objective of the work was to perform a computational analysis of the hybrid (steel-composite) carrier and compare the results with the original metal carrier. Static analysis, modal analysis and frequency response were solved. Computation was performed for three different relative positions of the carrier. Static stiffness, natural frequencies and dynamic compliance have been calculated. The results were verified by an experiment performed on a scaled-down model of the carrier. Modern software products, namely MSC Patran, MD Nastran, Matlab and ProENGINEER, were used for the calculation.
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Strain and stress analysis of the car buffer zone under impact loading
Nedělka, Pavel ; Obdržálek, Vít (referee) ; Vrbka, Jan (advisor)
The master thesis deals with a stress-strain analysis of the front crash structure of a race car by using the finite element method. The structure is loaded by an impact loading. This type of analysis belongs to the transient analysis so the explicit formulation of the finite element method is used. The LS-DYNA software was used for calculations. The goal of this thesis is to express the influence of the crash structure to the change of the car's kinetic energy as well as the amount of absorbed energy in case of frontal impact.
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