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Creating a computational model for stress-strain analysis of parts of generator
Sedláček, Radek ; Fučík, Karel (referee) ; Návrat, Tomáš (advisor)
This thesis focuses on creating of a computational model for stress-strain analysis of parts of a generator. Computational model is parametric and it allows use of various geometric variants of the shaft and rotor lamination. Parametric computational model in APLD language is compiled in the attached sheet of software MS Excel after entering input values. After solving in software ANSYS 14.5 are results imported into MS Excel sheet for further post processing.
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Analysis of residual stresses in arterial wall
Novák, Kamil ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
This thesis deals with computational modeling of the influence of residual stresses in idealized geometry of blood vessels and subsequent application of acquired knowledge to abdominal aortic aneurysm. In the terms of quality of the computational model, we reduced the uncertainties that are included in the computational model without considering the influence of residual stresses. The basic assumption of homogenization significant peaks of the stress between inner and outer vessel wall was met for each level of the computational model Methods that have been used are: deformation method (opening angle method), inverse mechanics of large deformations, fictitious temperature – for linear elastic material and hyperelastic material defined by the constitutive model. Numerical verification was carried out using program ANSYS.
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Finite element modelling of pathological changes in human vocal folds tissue and their influence on videokymograph
Martínek, Tomáš ; Matug, Michal (referee) ; Švancara, Pavel (advisor)
Master´s thesis deals with creating planar computational model of human folds, involving fluid-structure interaction. With this model, the influence of changes in vocal folds tissue layers (stiffness, thickness) and their effects on the videokymograph image are studied. Analysis of the results also deals with the evaluation of pressure at selected points below, between and above the vocal folds. The results indicate a possible similarity with the behavior of human vocal folds with pathology. Background research of vocal folds function, an overview of vocal folds pathology and summary of computational models are included.
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Influence of the surrounding tissue on the stresses in brain arterial aneurysms
Lipenský, Zdeněk ; Burša, Jiří (referee) ; Polzer, Stanislav (advisor)
This thesis is focused on stress in brain aneurysms. It consists of three parts. First part is aimed for gaining information about the topic from scientific resources. Next part consists of analyses of geometry of cerebral aneurysms on the computed wall stress. Analyses are performed on four basic geometrical models and results are being discussed. The risky areas in each investigated shape have been identified as well as the comparisons of stress between those shapes have been performed and the most dangerous shape among investigated shapes has been determined. Third part investigates the influence of surrounding tissue on the brain aneurysm. Conclusion of this thesis is that brain gray tissue has positive yet negligible effect on the computed wall stress.
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Stability analysis of swinging props turbines
Bukovský, Petr ; Navrátil, Petr (referee) ; Skalka, Petr (advisor)
Master thesis deals with a computing simulation of two props turbines lines. The thesis output is gaining maximum possible load, at which a commencement of deformation stability critical state for various geometrical imperfections has not arisen yet. The calculation has been done by FEM in two different ways: linear solution (using a calculation conversion into eigenbuckling) and nonlinear solution (using a FEM deformation option). Result analysis compares both methods outcomes. Safety factor for the props operation has been proposed taking into consideration known influences on operating state.
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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 analysis of the total hip joint endoprosthesis head under oblique loading
Janovský, Martin ; Janíček, Přemysl (referee) ; Fuis, Vladimír (advisor)
This diploma thesis is concerned with the stress analysis of the total hip joint endoprosthesis ceramic head under oblique loading. Load was obtain from experimental in vivo measurement on three patients, whereas two of them was the same weight. As input variables were use contact forces, especially knee bend and standing on one leg. Furthermore they will be considered shape deflections from ideal cone, especially circle deviation, cone deviation and cone plus circle deviation together.
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Stress analysis of the total hip joint endoprosthesis head under ISO 7206-5 loading
Varga, Jozef ; Hlavoň, Pavel (referee) ; Fuis, Vladimír (advisor)
The aim of this work is to analyse axisymetric tasks by norm ISO 7206-5, which is used to determination of static strength of ceramic heads. In the numeric analysis there will be considered form variances from nominal conicalness and circularity of stem sections i.e. possible variances caused by production. Furthermore form changes of recess inside of the head measured on real samples will be considered. All these variances from nominal values are necessary to analyse in more details, because they can participate in destruction of ceramic heads. The stem system, ceramic head and load cone (DHK) will be simulated as a 2D axisymetric task and 3D quarter symetrical task. That is why is necessary to undertake also comparing analysis of 2D and 3D tasks and compare results or eventually evaluate the error. This problem is solved using of Finite element System ANSYS 11.0.
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Literature search of possibilities of computational modelling of brain aneurysms
Lipenský, Zdeněk ; Polzer, Stanislav (referee) ; Burša, Jiří (advisor)
This bachelor thesis is focused on gathering general information about a cerebrovascular disorder called Cerebral Aneurysm (or also Brain Aneurysm) which is a medical condition consisting in an abnormal bulging outward of one of the arteries in the brain. The initial attention is given to the human cardiovascular system, a description of which is fatal for understanding the problem of brain aneurysm. The next attention is focused on the solution of eliminating the tension within the aneurysm by using knowledge gained in lectures "Flexibility and Strength II" during the sixth semester. The last chapter shows a summary of three works dealing with computational modeling of cerebral aneurysm.
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