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Computational simulation of cross-roll leveling of rods
Benešovský, Marek ; Vrbka, Jan (referee) ; Petruška, Jindřich (advisor)
Final thesis describes two variants of computational models to simulate cross-roll leveling of rods, which are based on the Lagrangian approach to describe the continuum. Implementation of both variants was performed in ANSYS software, and their main difference lies in the choice of the type of elements for the discretization. An integral part of this thesis is the description of the principle, which is an evaluation of the curvature of the rod after completion of the simulation leveling. In the other part of the work are presented the results, which are then compared with realized experiment and simulation algorithm for cross-roll leveling based on the Euler approach. The final part is dedicated to the optimal settings of the leveller.
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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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Strain, stress and strength analysis of the frame construction.
Kysilko, Vít ; Damborský, Petr (referee) ; Vrbka, Jan (advisor)
The bachelor´s thesis is intent on the computation of a plane frame which is used for test the resistance of composite tubes to a changing pressure. As a computational model I used simplified frame loaded by solitary forces which work eccentrically from the axis of symmetry of the frame. Because I cannot exactly use the theory of simple elasticity and strength in this task I make two calculations with various shapes of midline. This is twice internally statically indeterminate task, appropriate deformation conditions were solved by Castigliano’s theorem. Bending stress is dominant but in calculation is also composed energy of normal and displacement forces. Inspection of cyclic fatigue was made in possible hazardous places. Analytic calculation was carried out in MAPLE 12 and it was compared with Finite Element Method analysis with Ansys Workbech 12 software.
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Strain, stress and strength analysis of the truss construction.
Hladký, Maroš ; Horníková, Jana (referee) ; Vrbka, Jan (advisor)
The thesis is focused on strain, strength, and strain analysis of planar truss construction. The purpose of this work is to determine the load on each rod, and to assess the safety against limit states. After determining the primary characteristics, the structure will be modified and load and safety re-calculated. Depending on the outcome, the design will be changed again. Next, will be destined gravity affect on the design and impact of production inaccuracy. Deformation of structure will be calculated.
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Strength design of the aircraft spur
Profota, Martin ; Vosynek, Petr (referee) ; Vrbka, Jan (advisor)
This master thesis deals with computational stress-strain analysis of the tailskid of airplane L410 NG with main focus firstly the check current design of the tailskid and then the design another design solution with the able to absorb as much as possible the deformation energy. Solution of this problem is performed using computational modeling utilizing numerical simulation of quasi-static and crash deformation load of the tailskid with using explicit Finite Element Method (FEM) in program ABAQUS v6.14. After the introduction with problem situation and tailskid assembly introductory part is devoted to the research study of various designs of the tailskid for different types of airplanes. There follows these theoretical general principles of thin-walled structures and buckling of them. Before the creating of the computational model itself, the explicit form of the Finite Element Method is better described. The conclusion of this thesis deals with the mutual comparison of the most advantageous design variants of the tailskid and the selection of the most suitable one of them for the airplane L410 NG.
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Stress, strength and strain analysis of the crane truss construction.
Nedělka, Pavel ; Borák, Libor (referee) ; Vrbka, Jan (advisor)
This bachelor thesis deals with stress, strength and strain analysis of the plane crane truss construction. The aim of this work is the calculation of forces for the simple frame with the help of joint equilibrium equations. These forces will be modified by further construction treatment. This treatment turns the simply frame into the hyperstatic system. The obtained values data are the input data for the design of geometry of particular bars. The unknown dimensions will be determined by two strenght limit states. These limits are: limit state of elasticity and limit state of stability. Then we will make the strain analysis. It will determine the displacement in the action of the force, the effect of actual clearance as well as the brace failury effect to the construction safety. Further will be determined the influence of the weight of the construction to the strenght.
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Strain and stress analysis of the car front part under impact loading.
Hrubý, Jaroslav ; Vémola, Aleš (referee) ; Vrbka, Jan (advisor)
This work deals with the stress and strain analysis of the car front part of Škoda Octavia II. generation under impact loading using an explicit formulation of finite element method (FEM). The aim of this work is examination of resistance of the car front part under this impact loading and comparison of the data, which were get out of the FEM simulation of the car impact on the rigid wall with methods, which are used in forensic engineering. The comparison of the FEM simulation of the car impact on the rigid wall will be provided with the correlation method and with the method of energetic grid.
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