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A simplified model of the pad deformation of the journal bearing
Janiš, Tomáš ; Cabaj, Gabriel (referee) ; Pokorný, Jan (advisor)
The presented bachelor thesis deals with the calculation of deflection of a pad of a hydrodynamic radial bearing with tilting pads. This type of bearing is described by its characteristics, which are determined by means of simulations. Knowledge of these characteristics is important for predicting the behaviour of bearings in service and for the design of equipment using these bearings. The bearing characteristics are strongly dependent on the thickness of the lubricating film. This is in fact very thin and is therefore affected by the slightest deflection of the pad. This paper therefore deals with the calculation of pad deflection. With this calculation, the effect of pad deflection can then be included in downstream simulations to determine the bearing characteristics. The inclusion of this effect results in more accurate simulations. For this reason, a computational model of bearing pad deflection is developed. This model is based on the differential equation of the deflection line assuming small deformations. The temperature effects due to lubricant heating and the pressure effects due to bearing pad loading are included in this calculation. The deflection results from these loads are further compared with the results obtained by the finite element method. This comparison did not achieve the required compliance.
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A review study of dental mini-implants
Pernický, Vojtěch ; Hrubanová, Anna (referee) ; Marcián, Petr (advisor)
This thesis focuses on the study of dental mini-implants, which are becoming a popular choice for replacing missing teeth and retaining overdentures. The insertion of mini-implants is a less invasive procedure that minimizes damage to bone tissue, which shortens the patient's recovery time. One of the key advantages is the possibility of immediate loading of the implant. However, the smaller diameter of these implants means a smaller surface area for osseointegration, which can negatively affect their stability and functionality. This thesis deals with the analysis of deformation and stress states by using computational modeling. The results of this analysis are compared with standard implants to evaluate the mechanical behaviour of mini-implants and their interaction with bone tissue. Based on the results of the analysis, it can be said that the diameter of the implant significantly influences its deformation-stress states.
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Computational modeling and utilization analysis of materials with shape memory for applications in the field of mechatronic actuators
Ševčík, Roman ; Skalka, Petr (referee) ; Ševeček, Oldřich (advisor)
This bachelor’s thesis deals with a computational modeling of shape memory materials and their applications in actuators. The recherche part of the thesis describes the basic principles of function of the shape memory materials, different possibilities of their utilization, their modeling and also principles of designing actuators using these materials. The next chapter deals with a creation of the computational model in SW Ansys, testing of this model and its subsequent use for modeling of the chosen actuator. The next step is the testing of the selected actuator model under different conditions of its computational analysis. The last chapter describes a general method and approach for the modeling of shape memory materials in SW Ansys, recommended settings of the computational analysis and application potential of the chosen actuator.
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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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Methods of fixation of the upper limb fractures
Litera, Jan ; Marcián, Petr (referee) ; Florian, Zdeněk (advisor)
The presented bachelor thesis is focused on current methods of a fixation of upper limb fractures. Part of the thesis is a literature review and a description of the upper limb anatomy. This is necessary to solve the problems associated with upper limb fractures. The history of the treatment of upper limb fractures enables to gain an insight and a benefit of the current methods of the fixation of the upper limb. Based on the acquired knowledge, there is created a simple computational model of a humeral fracture fixation using a LCP and a classical plate. The computational model for the specific load models was solved in the Ansys Workbench 18.2 computing system. The biomechanical analysis based on the results presentation of the solution of the described simple model showed differences between the application of the LCP and the classical plate.
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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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Virtual Prototypes of Drivelines
Janoušek, Michal ; Dundálek, Radim (referee) ; Slimařík,, Dušan (referee) ; Píštěk, Václav (advisor)
The thesis deals with computational modelling of heavy duty off-road vehicle driveline components. The thesis is divided to two main parts. The first part deals about modal analysis of selected driveline components. MBS computational study was performed based on modal analysis results. The second part of thesis deals with experimental verification of computational model. Pass-by noise and vibration measurement was performed. Measured signals were processed in frequency domain to find noise and vibration sources.
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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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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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