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Deformation and stress analysis of the parts of the total replacement of the trapeziometacarpal joint
Svojanovský, Tomáš ; Marcián, Petr (referee) ; Fuis, Vladimír (advisor)
The presented diploma thesis builds on author’s bachelor’s thesis of the similar name which was focused, in particular, on rhizarthrosis. Because of this joint disease, implantations of the total joint replacement are performed. The bachelor’s thesis also served as a familiarization with the finite element method and contact analyses issues, giving a theoretical framework for this diploma thesis. As opposed to that, the diploma thesis aims entirely at deformation and stress analysis of the total replacement. The main objective is to carry out analyses of different variants of geometric models. In addition, there is a tendency to analyze contact pressures of advanced model concerning all the total replacement, bone tissues, ligaments and tendons guaranteeing the static equilibrium of components. The bachelor’s thesis has been developed in ANSYS Workbench, whereas the diploma thesis in ANSYS APDL. Work in APDL allows user to control better over the entire computational process, however, requires more skills and theoretic knowledge. Contact analyses bring a lot of problems associated with convergence of procedures and accuracy of results. Therefore, explanations of important terms and set of recommendations are included for the purpose of easier solving of the contact problems.
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Evaluation of elastic parameters for models of isolated cells
Krbálek, Jaroslav ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
This diploma thesis focuses on computational modeling of the cell mechanical tests. The goal of this thesis is to build a cell model and to simulate compression test on this model. If necessary, the model should be adjusted so the model reflects real cell behavior. It was created the cell model reflecting cytoplasm, nucleus, membrane and cell cytoskeleton. Cytoskeleton was modeled as tensegrity structure. After this, the pressure test was simulated on this model. The behavior of the cell model and real cell was compared using the stress force. The stress force - cell deformation curve was markedly different for the cell model and the real cell. For this reason, the cytoplasm material model was adjusted. The difference between the curves was acceptable after this modification. It was found during computations that the cytoskeleton model influence on the cell load is minimal. These results does not reflects real cell behavior, which means that the model is considered inadequate for performing stress load simulation.
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Stress - strain analysis of save premolar tooth
Sáblíková, Zdeňka ; Fuis, Vladimír (referee) ; Florian, Zdeněk (advisor)
This diploma thesis deals with stress-strain analysis of healthy and save tooth. Defor-mation and stress of tooth system with a part of jawbone was solved by calculating method, FEM in computing system ANSYS Workbench 11. Stress-strain analysis of save of tooth was performed in twenty-five ways describing various classes and sizes of cavity, filling material and model of connection between the filling and the tooth.
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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.
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Crack Propagation in Railway Wheel under Operating Conditions
Navrátil, Petr ; Schmidová, Eva (referee) ; Fuis, Vladimír (referee) ; Janíček, Přemysl (advisor)
This doctoral thesis was written under supervision of my supervisor Prof. Ing. Přemysl Janicek, DrSc. and under supervision of my specialist supervisor Ing. Petr Skalka, Ph.D. The thesis deals with the influence of various operating conditions on crack behaviour in in a wheel rim and/or tire. The dissertation topic was motivated by cooperation with Pardubice University, Faculty of Jan Perner. The first part of the thesis presents a literature search, which provides a current state-of-art in the field of contact loading, crack propagation behaviour under mixed-mode and thermal field generated during braking. The next part of thesis deals with the solution of the given problem and the obtained results are presented. Specifically, crack behaviour under various operating conditions including the crack growth rate is simulated. Also, an influence of thermal field on crack is investigated. The linear elastic fracture mechanics approach is considered to treat the above mentioned problems. Last part of thesis summarizes the obtained results which are discussed in a broader context.
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Mechanical analysis of the subsystem of the tower crane
Urbánek, Roman ; Venský, Jiří (referee) ; Fuis, Vladimír (advisor)
The bachelor thesis deals with the solution of a subsystem of a tower crane with a passive effect (NNTP). First part describes tower cranes and their parts. The following part is a description of the theoretical and physical laws of statics and dynamics. In the practical part, various states of motion of a specific modeled subsystem are calculated, which shows a trolley of the tower crane. The aim of the calculation of each configuration is to determine the numerical values of the contact forces in the links, to analyze the dynamic quantities and to evaluate the functionality of the links. Numerical values of unknown parameters were calculated by solving a system of linear equations in the calculation software Matlab.
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Stress - strain analysis of jaw with decrease bone tissue
Krpalek, David ; Fuis, Vladimír (referee) ; Florian, Zdeněk (advisor)
This diploma thesis deals with stress - strain analysis of jaw with decrease of bone tis-sue. At first was created a model of geometry using graphic program Rhinoceros 4.0 upon acquisition by the 3D scanner. That was converted to the computational system ANSYS Workbench 11 which uses for solving the finite element method (FEM). Solving was executed with homogenous, linear and isotropic material model of bone with different characteristics for compact and cancellous bone. Forces of the three working muscles, which participate on chewing, were given on the basis of the force and moment balance mandible. Solving was executed for 12 variant simulating occlusion in places, where was earlier found teeth.
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Design of sand blasting machine modification
Klár, Pavel ; Fuis, Vladimír (referee) ; Krejsa, Jiří (advisor)
This thesis is focused on design and implementation of structural adjustment of sandblasting machine with regard to the requirements of resolution. The first part consist of short study describes a blasting technology and various types of blasting machines. Second part – practical part consists of problem analysis and setting goals to be achieved. The main goal of the design is to not influence the machine and to limit presence of the operators by modification in the actual process of sanding. There is also detailed design of solution’s proposal which fulfills the specified goals and is supported by calculations. Descibed design was realized and preliminary results suggest that pre-defined goals are met.
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Stress and deformation analysis of railway bridge over the Svratka River
Kovář, Jaroslav ; Žák, Stanislav (referee) ; Fuis, Vladimír (advisor)
This thesis deals with stress and strain analysis of real truss bridge structure. This structure is modelled as plane bar system. The opening part dedicates to theory, which is further used for calculations. The calculation part dedicates to compare statically determinate and indeterminate variation of structure for load by own weight and passage of the train. Analytic calculations are numerically verified with program ANSYS. In thesis is assessed concentration of stress, when the rivet drops out of the structure. The next part of thesis dedicates the spatial model of bridge, which is compared witch plane model.
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Failure probability of the ceramics part using Weibull weakest link theory
Kovář, Jaroslav ; Návrat, Tomáš (referee) ; Fuis, Vladimír (advisor)
This thesis compares Weibull weakest link theory with inclusion of one and all three principal stresses. Principal stresses needed for this theory were calculated with finite element method. The informational research is in the introduction of this thesis. It includes ceramic materials, Weibull weakest link theory, Gaussian quadrature over spherical surface and ceramic head of hip joint endoprothesis. Theoretical part is used for next calculations of probability of failure. The probability of failure of ceramic rod loaded by four-point bending is calculated in first calculations. This task is solved as contact in the next step. Next part of this thesis is about selection of suitable method of numerical integration. This method will be used in the calculation with all three principal stresses. The results of calculation with all three principal stresses are compared with the results of the calculation which includes only first principal stress. Firstly, this is done for cylindrical body and then used on head of hip joint endoprothesis. In the last part of this thesis, probability of fracture of head hip joint endoprothesis with shape deviation of nominal conicity is calculated.
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