National Repository of Grey Literature 55 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Stress-strain analysis of the railway bridge in Zahrádky near Česká Lípa
Abdul moghni, Abdul rahman ; Vosynek, Petr (referee) ; Fuis, Vladimír (advisor)
Cílem této bakalářské práce je využití deformačně napěťové analýzy na Železniční most v Zahrádkách u České Lípy. Konstrukce mostu byla zjednodušena a vymodelována jako nosníková konstrukce. První část bakalářské práce byla věnována získávání vstupních dat a základních informacích z technické dokumentace mostu. V nosníkovém modelu bylo využito několik zjednodušení. První model považujeme za staticky neurčitý, zatímco druhý jako staticky určitou konstrukci. Každý model tedy obsahuje zátěž z důvodu vlastní váhy a zatížení způsobeno projíždějícím vlakem. Z důvodu objemnosti rovnic, využíváme k výpočtu software Maple. Zkontrolovali jsme i mezní stav vzpěru pro oba modely, avšak jsme uvažovali pouze zatížení vlastní váhou a zatížení způsobeno vlakem. Po získání analytických dat bylo důležité tyto výsledky ověřit. Toto bylo docíleno využitím metody konečných prvku za pomocí programu Ansys. Veškeré výpočty byly provedeny pro 2D modely. Jediná výjimka je numerická sekce, kde byl přidán 3D model za účelem porovnání s 2D modelem.
Design of a new version of a trolley and docking station for channel racks
Pastrnková, Markéta ; Vepřek, Jiří (referee) ; Vosynek, Petr (advisor)
The master's thesis deals with the analysis of the current version of the trolley and the docking station of the channel racks and the design of modifications. The theoretical part describes the components of the storage channel system. There is also explained principle of pallet storage in this part. In the following chapter, several variants of the design of the lifting mechanism of the lifting platform are elaborated. The work also presents static structural analysis of the current version of the trolley and docking station, parametric study and topological optimization of one of the components. Static structural analyzes were partially solved in the finite element software RFEM by Dlubal Software s.r.o company, and mainly in the software ANSYS Workbench 2020 R2 by ANSYS, Inc. company.
Analysis of mechanical loads of selected structural parts of the excavator during operation
Busta, Michal ; Maňas, Pavel (referee) ; Vosynek, Petr (advisor)
This thesis is focused on the issue of computational modeling of soil harvesting while using the compact excavator from the company DOOSAN BOBCAT EMEA s.r.o.. The solution consists in creating two computational models in Rocky DEM and Ansys Mechanical. Rocky DEM software is used to solve the disconnection of soil by excavator components using the discrete element method. The outcome includes courses of forces and moments during the particular time of the individual joints of the model that was used. The obtained courses are then applied as an external load to the joint of a selected structural part of the analyzed model using a kinematic model in ANSYS Mechanical. The kinematic model consists of simplified geometry models of individual parts of the excavator arm, and a more detailed geometry model of the analyzed part of the arm. All the parts are connected to each other by rotational bonds representing joints. A static structural analysis of the mechanical stress is performed in ANSYS Mechanical for the prepared model during the simulated process. Finally, the selected structural part is assessed with respect to the elastic limit and fatigue strength.
Development of a methodology for calculating the residual stresses of a weldment in the Salome Meca software environment
Babišta, Jan ; Pokorný, Jan (referee) ; Vosynek, Petr (advisor)
The usage of welding in the process of manufacturing has become very widespread, mainly due to its low cost, versatility and the possibility of its automation. With its expansion comes higher demand for the possibilities of weld evaluation during the phase of design. Nowadays its possible to use tools based on finite element method for such evaluation. But the most commonly used tools are often very expensive. Therefore, the possibility of using Open-Source tool such as Salome-Meca to simulate the welding process as an alternative to commercial software was investigated. The first part of the work deals with the welding process and a description of the formation of residual stresses and deformations. It also deals with the description of the Salome-Meca software environment and the Code-Aster solver. In the next part the capabilities of the software in relation to problem of welding simulation are discussed. Furthermore, the goemetry of solved weldment, welding conditions, material properties and boundary conditions of the calculation are described. And finally, the individual solutions, their results and disadvantages of used approaches.
Study of MATLAB PDE toolbox usability in mechanics
Kováč, Patrik ; Vosynek, Petr (referee) ; Grepl, Robert (advisor)
This thesis deals with the practical usability of the PDE Toolbox in the MATLAB. It brieflydescribes the mathematical fundamentals of solution. The thesis presents the possibilitiesof PDE Toolbox in the creation of the model, geometry, boundary conditions, mesh and displayof results. The PDE Toolbox results from selected tasks from static, modal and transientmechanics and thermomechanics are compared with the analytical solution or with the FEMsimulation from the ANSYS. The main part deals with the evaluation and generalizationof results.
Comparative analysis of physiological, degenerative and postoperative lumbar spine using computational modeling
Krejbychová, Adéla ; Návrat, Tomáš (referee) ; Vosynek, Petr (advisor)
This diploma thesis deals with the comparative analysis of the physiological, degenerative and postoperative state of the lumbar spine. The problem was solved by computational modeling using the finite element method. For this solution, it was necessary to create appropriate computational models. The spine physiological state was compared with cases of the lumbar spine with different levels of spondylolisthesis, cases of the lumbar spine with different sacral angles, and cases of lumbar spine with applied fixators. Based on the performed analyses, it was found that spine degenerative state has a great influence on the distribution of stress in the vertebral discs and the vertebra itself. Compared to the physiological state, with increasing level of the spondylolisthesis the stress in the vertebral discs increases, while the stress in the vertebral section decreases. Furthermore, the spondylolisthesis affects the force flow. The higher the level of the spondylolisthesis, the more the force flow is shifted onto the posterior articular ligaments. The best results in terms of the spine physiological state were achieved with the applied fixator model.
Analysis of the effect of damping on the magnitude of the response during dynamic headlamp excitation
Lukáš, Jan ; Biskup, Martin (referee) ; Vosynek, Petr (advisor)
The aim of the submitted diploma thesis is the magnitude determination of the headlamp response to the dynamic excitation. Currently it is necessary to measure this response, because it is one of the assessed criteria of quality of the headlamp. When comparing results of the experimental measurement and the computational modelling, a good consensus of resonant frequencies is observed, but there are significant differences in acceleration amplitudes. The cause of this is the variable damping value. The theoretical part of the thesis deals with polymeric materials, basics of oscillation and damping. It serves to understand the mechanisms, which influence the results of the experimental measurement. The practical part is dedicated to the procedure of the computational modelling and the experimental measurement implementation. The analysis of the experimental measurement results leads to an ascertainment of nonlinearities, which influence the headlamp behaviour. The results of a sensitivity analysis of the computational modelling are used to create curves, on the basis of which the damping is estimated. The inclusion of the estimated damping into computational modelling leads to reduction of the compared differences of the acceleration amplitudes. The conclusion of the thesis contains the recommendation for the damping determination during the computational modelling of the headlamp.
Analysis of the influence of pressing force on the weld joint strength of the composite component
Litera, Jan ; Sedláček, Stanislav (referee) ; Vosynek, Petr (advisor)
Nowadays, components made of metallic materials are increasingly being replaced by components made of plastics or composites with a polymer matrix. This is associated with the issue of production processes such as pressing or welding, i.e. the influence of process parameters on the output properties of the product. The presented thesis deals with the issue of the combination of pressing and welding of a composite part, specifically the influence of the pressing overlap on the strength and tightness of the welded joint. The first part is focused on a search of available literature related to the problem. The second part deals with solving the problem using experimental modeling. Part of this chapter is inclusion of computational modeling in the design of experiment, detailed measurement of essential dimensions, microtome analysis and statistical processing and evaluation. The third part focuses on the creation of a method for evaluating the strength of the weld based on the pressing overlap using computational modeling. Essential part is also validation of the computational model based on previous experimental measurements. Finally, two methods for evaluation of the weld strength are presented. The first works on the basis of computational modeling and the second on the basis of experimental modeling. At the same time, the presumptions of usage of the created methods and their drawbacks are pointed out. Furthermore, the possibilities of their implementation in the initial design of the welded joint and the proposal for the next procedure are described.
Analysis of the influence of the Common Rail low-pressure connector parametres on its leak tightness
Ščerban, Bedřich ; Vosynek, Petr (referee) ; Petruška, Jindřich (advisor)
The aim of this theses is a sensitivity analysis of the tightness properties of the press-fit joined of the fuel pressure vessel Common Rail and the low pressure connector. Possible solutions were analyzed, where the fractional factorial design of a numerical experiment resolution four was chosen. Results of the thesis are statistically significant factors used in formulating the construction change recommendations.
Computational modeling of 3D printing structures made of PET-G material
Michálek, Mojmír Cyril ; Halama, Radim (referee) ; Vosynek, Petr (advisor)
Master’s thesis deals with computational modeling of 3D printing process done by FDM method made from PETG material using finite element method. Research section contains a brief description of 3D printing process modeling possibilities using finite element method and summarizes fundamental mechanical properties of thermoplastics. In practical section there is an evaluation of specimens printed of PETG material tensile tests. Further there is performed a sensitivity analysis of various influences on vertical imperfection of printed part Idler and is done its design modification, which is based on results of this analysis.

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