|
|
Stress-strain analysis of artery with atheroma
Maša, Marek ; Návrat, Tomáš (referee) ; Burša, Jiří (advisor)
The main goal of this diploma thesis was the stress-strain analysis of iliac artery with atheroma.This problem was solved using finite element method (FEM).For the calculation purposes three two-dimensional models were created. The geometry was gained from transversal sections through the iliac artery with ateroma. This geometry is educed from used literature review. The main calculation process was run by ANSYS 11.0 program system.
|
|
|
Contribution of technical equipments to treatment of blood vessel diseases
Laštůvka, Jan ; Návrat, Tomáš (referee) ; Burša, Jiří (advisor)
The goal of this bachelor’s thesis is an introduction to the anatomy and pathology of vascular system and providing an overview of technical equipment used for examination and treatment of blood vessel diseases. Using two type of blood vessel implants it illustrates the process of computation during the phase of creating a concept. In the former case the influence on blood flow and healthy blood vessel behaviour when using bifurcated blood vessel prosthesis is assessed, in the latter case the projecting computation of biflex stent construction is examined.
|
|
|
Influence of process parameters in forward extrusion on the die loading
Pokorná, Jana ; Návrat, Tomáš (referee) ; Petruška, Jindřich (advisor)
One of the decisive factors of effective using of forward extrusion technology is lifetime of forming tools. Die is very loaded forming tool which loading and therewith related lifetime can be significantly affected by its construction. Construction also affected quality of extruded material. Finete element method allows to simulate this process and assess force which is needed to extrusion and state of stress in die and extruded material. Numerical simulation was realized in program ANSYS 11.0. Influence of reduction, angle of reduction, lenght of extruded material, rounding transition of die parts, extruded material and friction coefficient on die loading and emergence of cracks in extruded material was set in this diploma thesis. Results can be used to die construction optimalization.
|
|
|
Stress-strain analysis of lower limb prosthetic
Musilová, Kateřina ; Fuis, Vladimír (referee) ; Návrat, Tomáš (advisor)
This master thesis deals with lower-limb prosthesis. The aim of the first part of this work is stress-strain analysis of trans-tibial prosthesis, which is understand without prosthetic socket and the foam prosthetic feet. Analysis is made using finite element method in ANSYS Workbench 12.0 software. For the purpose of setting up the computational model it is necessary to make few partial models. Model of geometry of the prosthesis is made in SolidWorks 2009. Based on the outputs of stress-strain analysis and the results evaluation, the critical component is chosen and this one is evaluated according to limite state for fatigue. The algorithm of evaluation of named component in the state of high cycle fatigue is discussed in the second part of this thesis.
|
|
| |
|
|
Stress-strain analysis of a bar systems using finite element method
Fodor, Ján ; Fuis, Vladimír (referee) ; Návrat, Tomáš (advisor)
The aim of this bachelors thesis is primarily programming of algorithm for solving bar systems (i.e. trusses) using finite element method. Programming language Python and his modules NumPy, SciPy and Matplotlib are used . The results thus obtained are verified in the program ANSYS . This work also gives a brief overview of commercial and freely accessible scientific software. Finite Element Method is a numerical method used for solving technical problems in mechanical engineering, structural engineering, electrical engineering and related fields.
|
|
|
Pevnostní posouzení konstrukce výřezu dveří přetlakovatelného habitatu pro extrémní prostředí
Sláma, David ; Šálený, Vratislav (referee) ; Návrat, Tomáš (advisor)
Main goals of this master thesis are following: to perform the state of the art research of overpressure constructions (especially space habitats, plane fuselages); to create an own concept of the functional inside ending (hole) in the sandwich panel for a door; to perform stress-strain analysis of this concept; to perform the design optimalization of this concept in order to minimise the weight. To solve the problems above software Ansys 17.2 is chosen, because it allows to: model the material of the honeycomb core of sandwich panel as homogenous linear orthotropic material; evaluate reserve factors of all critical limit states; perform the design optimalization; perform Monte Carlo simulation. First and second design optimalizations discover, that with defined parameters: 0,635 mm width of aluminium sandwich face sheets and inner overpressure 0,1 MPa, a creation of the model, that would be safe by changing the values of design variables is not possible. Specifically, the maximum value of shear stress on the glued areas between aluminium face sheets and honeycomb core is higher than the shear strength of the glue. Therefore, two new concepts are created. First for inner pressure 0,03 MPa and bigger width of aluminium face sheets 3,175 mm, second for inner pressure 0,02 MPa and same width of aluminium face sheets 0,635 mm. For both these concepts, an overall reserve factor is calculated. First, the value of an overall reserve factor is calculated deterministically. Secondly, the value of an overall reserve factor is calculated stochastically considering the variance of material properties of the honeycomb core ± 10 % by Monte Carlo simulation. An overall reserve factor of the concept with inner pressure 0,02 MPa is determined as 1,21. An overall reserve factor of the concept with inner pressure 0,03 MPa is determined as 1,20. The weight of the concept for inner pressure 0,03 MPa is though 4 times bigger than the weight of the concept for inner pressure 0,02 MPa. In the concept for inner pressure 0,02 MPa the maximum value of HMH stress in aluminium components is critical, stochastically considered material properties of the honeycomb core don’t have a significant influence on this value. In the concept for inner pressure 0,03 MPa the value of maximum shear stress on the glued areas between aluminium face sheets and the honeycomb core is critical, stochastically considered material properties of the honeycomb core have a significant influence on this value. In the concept for inner pressure 0,03 MPa an absolute error of overall reserve factor is 8 % (overall reserve factor calculated deterministically was 1,28) which is significant. Monte Carlo simulation is also used to find that the value of Poisson ratio XY of the honeycomb core doesn’t have statistically significant influence on all limit states. Value of the reserve factor of the honeycomb core is higher than 2 in both concepts. Monte Carlo simulation discovers that this value can be significantly lower. Using Tsai-Wu failure criteria the reserve factor in the concept for inner pressure 0,02 MPa is determined as 2,72 deterministically x 2,41 stochastically (absolute error 31 %), in the concept for inner pressure 0,03 MPa the reserve factor is determined as 6,85 deterministically x 6,17 stochastically (absolute error 68 %).
|
|
|
The usage of Salome Meca workbench for task solution in the field of solid mechanics
Anděl, Tomáš ; Návrat, Tomáš (referee) ; Vosynek, Petr (advisor)
Presented bachelor’s thesis focuses on solving basics tasks in the field of solid me-chanics by the finite-element open-source software Salome Meca. The theoretical background of finite element method (FEM), general explanation of basic expressions and brief summary of today’s used open-source and commercial software too is intro-duced in the opening part of the thesis. The brief overview of Salome Meca compu-ting environment and then file of individual tasks solved by using this software are followed. Acquired results are later compared with the other numerical software (ANSYS Workbench) or with analytical solutions.
|
|
|
Summary of FEM aplication on the basis Open Source
Tománek, Jiří ; Vosynek, Petr (referee) ; Návrat, Tomáš (advisor)
This work focuses on the summary of currently available FEM applications on the Open Source basis which are freely available on the Internet. There are three programs presented (Salome, Roshaz and Ansys) and in each of them there was an easy simple plane performed and demonstrated. In the final part, a comparison of the results and the procedures for the award plane task in the three above mentioned programs was carried out.
|
|
|
Strain-stress analysis of fixed bone of foot
Zapletal, Jakub ; Fuis, Vladimír (referee) ; Návrat, Tomáš (advisor)
This diploma thesis deals with analysis of the rigidity of different variations of foot fixations. In the thesis there is a description of elementary anatomy of foot and its patology. Furthermore the possible corrections of hallux deformities and chosen fixators are described. The problem of analysis is soluted by the method of finite elements. The thesis also includes steps of geometery model creation based on 3D scanning. Three differents types of fixations are compared in this thesis and each of them is created in two different levels of details. There is a comparation, analysis of final solutions and chosen influences on the rigidity in the conclusion.
|
guest ::
