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Optimization of HIC criterion during head impactor hit into the car hood
Kysilko, Vít ; Dobeš, Martin (referee) ; Vrbka, Jan (advisor)
Kvůli stále značnému počtu usmrcených chodců při dopravních nechodách se výrobci automobilů snaží pomocí vhodné konstrukce automobilu zmírnit následky způsobené nehodou. Při srážce impaktoru hlavy s kapotou automobilu dochází ke zpomalení impaktoru a na toto zpomalení je aplikováno HIC kitérium. HIC kritérium vyhodnocuje míru možnosti poranění hlavy při srážce. Cílem diplomové práce je výběr nejvhodnějšího časového průběhu zpomalení dětského impaktoru hlavy při srážce s kapotou automobilu Škoda Superb II z hlediska HIC kritéria a navržení konstrukčních úprav kapoty a okolních částí, které se dostanou do kontaktu tak, aby se skutečný průběh blížil teoretické fyziologicky přípustné variantě. Pro výpočtové modelování úlohy byla použita explicitní varianta metody konečných prvků (MKP). V první části práce jsou analyzovány data ze simulací úderu impaktoru dětské hlavy na kapotu auta, zvlástě pak analýzy částí energie spotřebované kapotou při srážce s impaktorem. Tyto data byly poskytnuté firmou Škoda Auto a.s. Další část se zaobírá návrhem křivek zpomalení se sinusovým, čtvercovým a trojúhelníkým tvarem. Dále je také navržena 2 vrcholová trojúhelníhová křivka zpomalení, jež je pomocí parametrů modifikovatelná. Optimalizací aproximovaného modelu geometrie kapoty automobilu při dopadu impaktoru hlavy na navržený model geometrie kapoty je zajištěno podobné shody s dříve optimalizovanou 2 vrcholovou trojúhleníkovou křivkou zpomalení. V další části je použit originální model geometrie kapoty automobilu Škoda Superb II a další optimalizace modelu geometrie kapoty vůči optimálnímu časovému průběhu zpomalení.
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Stress, deformation and safety analysis of the tandem bicycle frame
Profota, Martin ; Dobeš, Martin (referee) ; Vrbka, Jan (advisor)
Purpose of this work was the evaluation safety and pliancy of the frame structure tandem bicycle using method of basic elasticity with the help of the deformation and stress analysis. After introduction material and geometry of the frame tandem bicycle introductory part is focused on theoretical basis of calculation like beam assumptions, definition the beam, limit states, Sentence of Castigliano and Saint Venant's Principle. Before commencement actual analytical solution the spatial task was transferred to plane task and used model was simplified. Calculation related to two load states differing by way of load of frame tandem bicycle. For each load modes comparison with numerical solution by FEM was enabled. Mathematical software like Mathcad 14 and Maple 13 were used to analytical calculation. Check was performed by numerical solution in program ANSYS Workbench 14.5.
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Strength design of the press frame construction and the compliance calculation at the load position.
Dobeš, Martin ; Suchánek, Miroslav (referee) ; Vrbka, Jan (advisor)
The bachelor's thesis is intent on the calculation of a plane frame which is used for hydraulic press. The theoretical basis for the calculation is mentioned in the first part of this thesis. The calculation of a concrete exercise according to the task set in the bachelor's thesis is in the second part. As a frame model we used a plane frame with two crossbeams. The load on the plane frame is interpreted by solitary forces which work upon the crossbeams. The calculation uses the Castiglian's theorem to specify the unknown parameters from deformation conditions. The calculation considers flexion energy of tensity. In the next part of the calculation, we consider the energy of tensity caused by vertical and normal shear for comparison. Coordinates of the load position can be changed at will. The final results of the thesis are a concrete frame proposal and an examination of pliability of the frame. The calculation was carried out in MAPLE 11 software.
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Effect of Velocity of Impact Loading to Stress, Deformation and Durability of Component of Fuel Car System
Dobeš, Martin ; Horyl, Petr (referee) ; Návrat, Tomáš (referee) ; Petruška, Jindřich (advisor)
Passive safety is a well-known term. This term can be further categorized into different topics of the car passive safety, restraint systems, safety assistants (ABS, ESP, ASR, etc.). One of these topics is passive safety of the fuel system. Safety and tightness of the fuel system must be guaranteed even under non-standard conditions, for example a collision against a fixed obstacle. This issue is not often mentioned in the field of car safety. It is considered a standard. Passive safety of the fuel system is often ensured using various interesting technical solutions and devices, usually patented ones. The development of these solutions is supported by numerical simulations in different stages of development process. The doctoral thesis deals with impact loading of the plastic components of the fuel system, in particular Fuel Supply Module (FSM), which is mounted inside the fuel tank. The flange is the most important part of the fuel supply module from the car safety point of view. The flange closes FSM on the external side of the fuel tank. The thesis focuses on the finite element analysis of the complete or partial FSM, and the flange itself during impact loading. The main objective of this thesis are numerical material models, taking into account important aspects of the mechanical behavior of polymer materials during impact loading. There are a lot of ad hoc invented or standardized experiments described in this thesis. These experiments are used for estimation of the material parameters or comparison of numerical analysis vs real conditions, or tests. The solver LS-DYNA was mainly used for numerical simulations. The final results of this thesis brings new quantified knowledge about behavior of the Typical Semi-Crystal Polymer (TSCP), not only for impact loading. The practical part of this thesis defines new methodology for the numerical simulation approach of impact loading for FSM. This methodology is directly usable for new product development. A lot of numerical material models were developed and tested. The best results were achieved using numerical material model *MAT_24 with combination of *MAT_ADD_EROSION card. The limits and parameters for this numerical material model was estimated empirically during conducting experiments. The numerical material model SAMP-1 was partly solved in this doctoral thesis, but more detail study will be given in future works.
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Strain, stress and safety analysis of the car reinforcement frame
Dobeš, Martin ; Vosynek, Petr (referee) ; Vrbka, Jan (advisor)
This master thesis deals with the strain, stress and reliability analysis of the safety frame of racing car. The safety frame is a part of passive safety, which it becomes active in a case of impact. The safety frame makes a reinforcement of the car body and provides its sufficient stiffness. The first part of the master thesis is focused on determination of stress and strain states during the static loading tests and their analysis. The loading conditions are prescribed by homologation regulations of Fédération Internationale de l´Automobile (FIA). The problem is solved, making use of computational modeling utilizing the Finite Element Method (FEM). The first part of thesis is used for the stiffness and safety analysis under the static loading test. The second part deals with the effect of loading velocity on the stress and strain states using the computational modeling and solver LS-DYNA.
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Stress and strength analysis of the bicycle crank arm of a non-circular profile
Valenta, Tomáš ; Dobeš, Martin (referee) ; Vrbka, Jan (advisor)
This bachelor’s thesis deals with analytic solution of torque of a rectangular profile bar. Solution stands on Prandtl’s theory of torque of non-circular cross-section bar. Stress is thought about shear stress which is given by torsional moment and shear force, further about normal stress which is given by bending moment and tensile force. Application for this problem is stress and strength analysis of of the bicykle crank arm. Calculation is solved with MATLAB software.
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Effect of Velocity of Impact Loading to Stress, Deformation and Durability of Component of Fuel Car System
Dobeš, Martin ; Horyl, Petr (referee) ; Návrat, Tomáš (referee) ; Petruška, Jindřich (advisor)
Passive safety is a well-known term. This term can be further categorized into different topics of the car passive safety, restraint systems, safety assistants (ABS, ESP, ASR, etc.). One of these topics is passive safety of the fuel system. Safety and tightness of the fuel system must be guaranteed even under non-standard conditions, for example a collision against a fixed obstacle. This issue is not often mentioned in the field of car safety. It is considered a standard. Passive safety of the fuel system is often ensured using various interesting technical solutions and devices, usually patented ones. The development of these solutions is supported by numerical simulations in different stages of development process. The doctoral thesis deals with impact loading of the plastic components of the fuel system, in particular Fuel Supply Module (FSM), which is mounted inside the fuel tank. The flange is the most important part of the fuel supply module from the car safety point of view. The flange closes FSM on the external side of the fuel tank. The thesis focuses on the finite element analysis of the complete or partial FSM, and the flange itself during impact loading. The main objective of this thesis are numerical material models, taking into account important aspects of the mechanical behavior of polymer materials during impact loading. There are a lot of ad hoc invented or standardized experiments described in this thesis. These experiments are used for estimation of the material parameters or comparison of numerical analysis vs real conditions, or tests. The solver LS-DYNA was mainly used for numerical simulations. The final results of this thesis brings new quantified knowledge about behavior of the Typical Semi-Crystal Polymer (TSCP), not only for impact loading. The practical part of this thesis defines new methodology for the numerical simulation approach of impact loading for FSM. This methodology is directly usable for new product development. A lot of numerical material models were developed and tested. The best results were achieved using numerical material model *MAT_24 with combination of *MAT_ADD_EROSION card. The limits and parameters for this numerical material model was estimated empirically during conducting experiments. The numerical material model SAMP-1 was partly solved in this doctoral thesis, but more detail study will be given in future works.
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YouTube as a marketing tool
Dobeš, Martin ; Tahal, Radek (advisor) ; Stříteský, Václav (referee)
Although YouTube wasn't created until 2005, it became a leader in its field. It was visited by more than a billion people from all around the world which nowadays upload over 300 hours of videos every minute and watch about 5 million videos every day. Within a few years, it has become a world-wide phenomenon that has overlapped into many areas. One of these areas is marketing. The goal of this thesis is to explore YouTube as a marketing tool and use secondary resource research and expert interviews to create a comprehensive information base to help managers and marketers with comprehension of the YouTube landscape and show them best practice in the area.
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