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The usage of Salome Meca workbench for task solution in the field of solid mechanics
Nytra, Michal ; Návrat, Tomáš (referee) ; Vosynek, Petr (advisor)
Submitted bachelors thesis deals with solution of tasks of body mechanics in open-source workbench Salome Meca and FEM solver Code_Aster. In the beginning is short theoretical introduction to finite element method a basic theory to strength of materials. Then follows series of tasks, which will test solver and workbench. We will compare results with analytical solution (if exists), eventually with available commerical software Ansys. There are 3 static structural tasks (beams, axisymetric bodies). Next task is from dynamics, searching of natural frequencies and vibration of plate during harmonic excitation. The last one is steady-state-thermal combined with static structural. In the conclusion are summarized advantages and disadvantages of open-source softwares. Results of workbench Salome Meca vary from analytical solution maximal to 10 %, what is in engineering praxis suffcient accuracy.
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Printed Circuit Board Modal Analysis Results Comparison from Experimental and Computational Modeling
Oplt, Tomáš ; Vosynek, Petr (referee) ; Tošovský, Jiří (advisor)
Modal analysis of printed circuit board results, gained from computional and experimental modeling, have been compared. Anylyses have been performed on dummy boards (models without electronic components), created as one-layered at first, then as three-layered PCB. Board is usually clamped by its longer edges with wedgelock. In order to enable the realization of boundary conditions in computional and experimental modeling, real clamping has been simplified to simply supported. Computional models have used FEM elements, which are comomnly used in this type of problem. Determined results have been evaluated by comparing the experimental modeling results. Models‘ sensitivity on modification of element length and number of elements through thickness have been performed.
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Creating geometrical models of selected implants of hip joint
Kohoutek, Jan ; Vosynek, Petr (referee) ; Návrat, Tomáš (advisor)
According to the specification, the concept of the thesis is a research study, which is supposed to present global overview of the hip joint arthroplasty. It involves a short summary of basic methods used in biomechanical measurements of bone tissue and provides a comparison among isotropic homogeneous, isotropic inhomogeneous and orthotropic inhomogeneous material models and their impact on the results of the stress-strain analyses. In the thesis, there is also a short list of popular implants used in present times as well as a few examples of creating geometrical models of some prosthesis.
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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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Stress and strength analysis of steam turbine valve
Kořínek, Tomáš ; Vosynek, Petr (referee) ; Petruška, Jindřich (advisor)
This diploma thesis deals with the determination of lifetime and computational modeling of stress strain states arising in the body of the steam turbine valve. Due to the high temperature of the inlet steam, the creep of the material which fundamentally affects its final lifetime is also considered in the calculation. The lifetime is evaluated by four different procedures using the finite element method via the ANSYS software. The results are compared at the end of this work. One of the chapters is focused on solving the problem of the creep in the ANSYS software environment.
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Analysis of Response Variables of Bone Tissue under Mechanical Loading
Vosynek, Petr ; Daniel, Matej (referee) ; Janíček, Přemysl (referee) ; Návrat, Tomáš (advisor)
Dissertation summarizes the results of computational and experimental modeling in the field of biomechanics engineering. Analyses are focused on selected variables that complement or can supplement existing methods of prediction of bone fractures. In terms of computational modeling the variables are based on stress strain analysis. The greater part of the work has been aimed on experimental modeling which is used for monitoring the two dominant components of bone tissue, which are minerals and collagen fibers. The current most widely used variable for the description of bone loss (osteopenia, osteoporosis) is areal bone mineral density (BMD). This variable does not however provide any information about the change in total volume consequently change of mineral and collagen. Proposed mechanical values follow the loss of the two components during simulation of minerals loss (demineralization) and simulation of collagen loss (deproteinization) in vitro for long turkey bones
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Types of fatigue tests and methods of data processing
Lamrich, Richard ; Halabuk, Dávid (referee) ; Vosynek, Petr (advisor)
Bachelor thesis is focused on fatigue testing and creating of S-N curves. In the first part three main stages of fatigue life are processed in order of making theoretical knowledge needed. Next the thesis is focused on dividing methods for making these tests and machines that are used for these tests and shows under which circumstances they are appropriate to use. Last part is dedicated to methods of creating of S-N curves.
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Comparative analysis of the effect of nonlinearities on the lumbar segment stress/strain of the spine after correction of spondylolisthesis
Holá, Lucia ; Ščerba, Bořek (referee) ; Vosynek, Petr (advisor)
This final thesis focuses on the stress-strain analysis of the physiological, postoperative and degenerative state of the lumbar spine segment. The aim of this thesis is to implement nonlinear material characteristics into previously made computational models and to compare these two models. The solution is performed by computational modeling using the finite element method. The geometry model was made by modification of the previous model of geometry. The group of degenerative state models comprises of three different levels of spondylolisthesis, according to Myereding’s classification. Based on the performed analysis, it was found that the increasing severity of spondylolisthesis, as well as the change in material definition plays a huge role in the stress development in the intervertebral discs and in the vertebrae. The total deformation of the spine segment increases with the use of nonlinear material characteristics, as well as with the increasing variability from the physiological state. However, the stress distribution in the intervertebral disc decreases with the use of nonlinear material characteristics and in case of the vertebral stress distribution increases, unlike in the linear material models. The biggest similarity with the physiological state of the lumbar spine segment was found in the postoperative state using the spinal implants.
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