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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Deformačně napěťová analýza a hodnocení mezních stavů částí tlustostěnného potrubí v oblasti creepu. / Stress - strain analysis and creep assessment of the thick-walled tubular structures.

Zouhar, Michal January 2009 (has links)
This thesis deals with the stress-strain analysis of thick-walled pipe parts. The dimension series (characterized by the D/d ratio) of three components are solved, then a direct tube, a torus with constant wall thickness (arcus) and a torus with variable wall thickness (bend). At first, the internal pressure amount, when a fully plastic state for these components is created, is solved. The amount of the limit pressure is determined analytically, numerically and by appropriate normative relations. The results and stress diagrams of individual solutions are mutually compared. Furthermore, these components are solved in the creep and are exposed to the maximum allowable normative internal pressure for 200,000 hours according to the standard – the operating time of components. The place of the maximum equivalent creep strain and the place of the maximum equivalent stress is examined. In these places the principal stresses are depicted depending on the D/d ratio. The results and stress diagrams of individual dimension series are mutually compared. From the available literary sources the condition of the limit state reach is chosen, according to which the evaluation of the limit state reach for individual components is carried out.
32

Deformačně a napěťová analýza čelisti se zubním implantátem / Stress - strain analysis of jaw with tooth implant

Hamerníková, Martina January 2009 (has links)
This diploma thesis is oriented on a stress – strain analysis of the jaw bone with a screw dental implant. There is a literature search on this theme in the beginning of this work. Solutions deformation and stress the system lower jaw and implant was performed computational modeling, by using the finite element method. Modeling is part of the lower jaw with dental implants applied screw type Ankylos, Bränemark and implant with metric thread. The thesis is described in detail development of calculation model system and solutions. To create a geometry model of geometry Solidworks 2007 was used. To create calculation model and the solution was implamented in the computer systém ANSYS 11.0 and ANSYS Workbench.
33

Deformačně-napěťová analýza arteriálních aneuryzmat / Stress-strain analysis of arterial aneurysms

Tesařová, Petra January 2010 (has links)
The diploma thesis is focused on the creation of the aneurysm finite element model and the making of the aneurysm wall stess-strain analysis using ANSYS software. The model of abdominal aortic aneurysm geometry starts from the CT scan of the particular patient. In the thesis there are compared two chosen constitutive models, each of them appears from different mechanical tests done on human arterial fibre samples. Furthermore, a limiting condition for aneurysm wall structure damage is expressed. On the basis of the results of stress calculation in the aneurysm wall and the limiting condition, the safety coefficient and rupture factors risk are worked out.
34

Analýza mechanického chování synchronního generátoru / Analysis of mechanical behaviour of synchronous generator

Donát, Martin January 2010 (has links)
This Master’s thesis deals with analysis of mechanical behaviour of the synchronous generator and assessment of the possibility of reducing the mass of the frame of the generator. The aims of this work were: to perform the stress-strain analysis and modal analysis of the required model of the synchronous generator, to assessment influence of single part of the frame of the generator over its stiffness and design construction modification of the frame of the generator, which reduce its mass.
35

Deformačně napěťová analýza aortálních výdutí / Stress-strain analysis of aortic aneurysms

Man, Vojtěch January 2012 (has links)
This master thesis is focused on stress-strain analysis abdominal aortic aneurysm using ANSYS software. The model of abdominal aortic aneurysm are based on CT scans of five specific patients. The branching arteries are included to the model and one goal of this thesis is decision about their influence of the wall stress. In this thesis was used a hyperelastic materiál model, which is based on mechanical tests done on human arterial samples.
36

Biomechanická studie karpometakarpálního (CMC) kloubu palce ruky / Biomechanical studies carpometacarpal (CMC) joint thumb

Podsedník, Karel January 2013 (has links)
This master thesis deals with stress-strain analysis of carpometacarpal (CMC) thumb joint. It is a preliminary study, which was not analysed on BUT Mechanical and biomechanical institute yet. There is a comparative stress-strain analysis of CMC with applied total endoprosthesis and physiological condition. The model of geometry was created based on CT images and processed with using software Catia and Solidworks. The problem was solved in numerical FEM (finite element method) in software Ansys 13.0
37

Tvorba výpočtového modelu pro deformačně napěťovou analýzu prvků generátoru / Creating a computational model for stress-strain analysis of parts of generator

Sedláček, Radek January 2014 (has links)
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.
38

Návrh nového typu obvodového závěsu pro lopatky parní turbíny / Proposal of a new type of steam turbine blade attachement

Vrbický, Jiří January 2015 (has links)
This thesis describes design of new circumferential blade attachment on last grade of steam turbine and following stress-strain analysis by FEM with static and cyclic loading. It was created two new design of geometry, which were created based on existing and operating constructional solution of oblique double T blade attachment. It was made stress-strain FEM analysis on original design of blades. Its results served to realize change of construction. Their target was increase load capacity and service life of new types of blade attachment.
39

Biomechanická studie lidské dolní čelisti ve fyziologickém stavu / Biomechanical Study of Human Mandible in Physiological State

Borák, Libor January 2010 (has links)
This study deals with the mechanical aspects of human mandible in physiological state during the occlusion. The work is focused on evaluation of stress-strain conditions of bone tissue. The emphasis is paid to the interaction of teeth with the bone. In addition, contact pres-sures in temporomandibular joints during various loading conditions were determined. The analysis of material model of some parts of the system regarding their modelling-level is pre-sented as well. The problem concerning the evaluation of stress-strain states is solved by computational simulation using the finite element method. The presented work is a detailed analysis of the parts of the masticatory system and a thorough description of their modelling is presented. Special focus is paid to modelling of cancellous bone as well as of periodontal tissue which mediates the interaction between a tooth and the alveolar bone. Three-dimensional geometry of the mandible and all its teeth has been obtained by using the digitizing of real objects, namely by using of three-dimensional optical scanner. Three various modelling levels of the material of periodontium are assessed: Linear iso-tropic model, bilinear isotropic model and linear orthotropic model. Characteristics of these models are analyzed and especially nine new constants describing orthotropic model (which is almost absent in the literature) are proposed. Two-dimensional models are used for analysis of differencies in mechanical response of cancellous bone to the tooth loading. Two cases are considered: Cancellous bone as a ho-mogenous continuous model on one hand and with detailed trabeculous architecture model on the other. Computational model is divided into four basic cases varying in level of masticatory appa-ratus geometry: A – 2D geometry of bone; B – 3D geometry of bone segment with one tooth through three teeth; C – 3D geometry of whole mandible with the only tooth; D – 3D geome-try of whole mandible with all teeth. All basic cases are further researched in different varia-tions for different material models etc.
40

Optimalizace sací trouby násoskové vírové turbíny / Optimization of the siphon swirl turbine draft tube

Mach, Jiří January 2016 (has links)
The goal of this diploma thesis is to design a new shape of the draft tube, which will be easier to manufacture while maintaining good strength and hydraulic properties. First part of this thesis is devoted to the formulation of the problem, description of the swirl turbine, principle of operation, the basic variants of arrangement, also the function of the draft tube, its efficiency and other formulas. In the second part of this thesis is a CFD and strength analysis of the original design, also a new design is proposed and the possibility of optimization using ANSYS Fluent Adjoint solver.

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