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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.
41

Deformačně a napěťová analýza fixátoru dolní končetiny Orthofix / Stress - strain analysis of inferios limb with fixator type Orthofix

Mrázek, Michal January 2008 (has links)
This diploma thesis aims to create a stress strain analysis of Orthofix external fixator applied to lower limb. The introduction summarizes the background research in available scientific publications, targetting the alternatives of treatment, namely application and fixation solutions of long bones. Furthermore parametric models of the fixator and tibia are created in CAD system CATIA. The fixator model enables to create different geometric variations simulating possible fixator settings and moment load in the range of 1-10 Nm. These geometric and loading states of fixator are solved via FEM in ANSYS. Single versions of the states of Orthofix fixator are then subjected to the stress strain analysis.
42

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

Školník, Roman January 2008 (has links)
This diploma thesis is dealt with stress-strain analysis of jowl with teeth implants. Teeth implants when locked in place (jowl) have the ability to replace and be used in the same way as the missing teeth. The implant creates a pillar column in the buccal cavity and then the tooth cap or bridge is secured on the pillar column. In this diploma thesis it is described as a solution of stress and strain of two types of cylindrical teeth implants VNI. Thesis specializes on the influence of deviation implant from the vertical axis. The solution is accomplished in program ANSYS Workbench by Finite Element Method (FEM). The geometric models are made in program SolidWorks 2005.
43

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

Petrlíková, Helena January 2008 (has links)
This diploma work is oriented on the deformation and load stress analysis of the jawbone with the razor-blade dental implant of the company MTI. There is a literature search on this theme in the beginning of this work. Deformation and tenseness of the system is done by computerized method FEM. There is detailed description of creating the computational model in this work. The geometry model of the system was created in the 3D CAD design software SolidWorks. Discretization, model of constrains and load sets including own solution was created in the ANSYS Workbench. On the basis of solutions with different load sets, which are presented in this work, is created a deformation and load stress analysis for two razorblade implant of copany MTI.
44

Deformačně napěťová analýza tumorózní totální endoprotézy kyčelního kloubu / Stress-strain analysis of tumorous total endoprosthesis of hip joint

Vystrk, Tomáš January 2018 (has links)
Tumorous total endoprosthesis of hip joint is used for reconstruction of the limb affected by bone tumor and to regain its functnion. Longterm load conditions must be considered by the reconstruction and the joint mobility must be enabled. Suitability of the endoprosthesis depends on its construction considering shape, material and with this related mechanical properties. This thesis deals with creation of computational model and stress-strain analysis of tumorous total endoprosthesis of hip joint. There are two different types of endoprosthesis modeled in this thesis, each with three different length of resected bone replacement. Based on stress-strain analysis an assessment of possible limit states is made.
45

Deformační a napěťová analýza totální endoprotézy temporomandibulárního kloubu / Stress-Strain Analysis of Total Endoprosthesis of Temporomandibular Joint

Horňas, Jan January 2018 (has links)
The presented master’s thesis deals with the problem of the application of total endoprosthesis (TEP) during temporomandibular joint (TMJ) replacement. The implantation of TEP occurs due the severe TMJ disease (arthrosis, ankylosis, cancer) or its macrotrauma. Condylar prosthesis is fixed during the implantation by self-tapping screws to the mandible. This fixation causes a change of stress-strain behaviour of mandible, TEP and fixation screws. In the thesis is performed the stress-strain analysis by using computational modeling in use the finite element method (FEM). Analysis is performed for six different screws positions (the number of screws is unchanged) and for a variable the static friction coefficient (in range 0.1 to 0.11) between condylar prosthesis (CP) and fossa prosthesis (FP). Altogether, 36 variants of computational models were created. The stress strain analysis detected a substantial influence of the static friction coefficient value to final results of displacements, contact pressure on the articulation surface between the CP and the FP and also to von Mises stress of the CP. A substantial influence of different screws position is detected for von Mises stress in the screws and for von Mises strain in the cortical and spongious bone tissue.
46

Deformačně-napěťová analýza fixace kostí palce nohy / Strain-stress analysis of fixed bone of foot

Zapletal, Jakub January 2018 (has links)
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.
47

Výpočtové modelování napjatosti ve výdutích mozkových tepen / Computational modelling of stresses in intracranial aneurysms

Turčanová, Michaela January 2018 (has links)
The diploma thesis deals with the assessment of the prediction of brain aneurysm rupture based on its geometrical and material properties. In the first part of the thesis there is a~detailed research study of cardiovascular systems with a focus on the cerebral artery and aneurysm occurring on their bifurcates. The second part of the thesis is focused on the creation of two models of arterial cerebral bifurcation with the presence of aneurysm and on obtaining their geometry in unloaded state. Emphasis is placed on the most realistic constitutive model of the artery wall material based on real data from uniaxial tensile tests and on a suitably chosen blood pressure load. This blood pressure may be step-changed, for example, in bungee jumping. In the work, a calculation of the increase in blood pressure during the step-change is performed, which is subsequently used in calculations of tension in the wall of the cerebral aneurysm. In conclusion, the risk of rupture is evaluated in two model idealized brain aneurysms and a discussion of the credibility of the results is given.
48

Pevnostní analýza formy pro vysokotlaké odlévání / Strength analysis of mold for high-pressure casting

Ferenc, Filip January 2019 (has links)
This master thesis had been created at the instigation of Skoda Auto. a.s. tool design department, which designed a new concept of the diecast mold. For this new concept of construction mold was requested to describe its strain-stress behaviour. The main goal of this thesis was to run s-s analysis. According to results of s-s analysis the potentially risky location had been found and the recommendation of the design improvement had been made. The problem has been solved by Finite Element Method in software ANSYS Workbench. The output of the work is mainly used as a basis for the design of high-pressure casting molds of S. A. a.s.
49

Konstrukční návrh pryžové spojky pro aplikaci v kolejové dopravě / Design of a rubber coupling for railway applications

Blach, Jiří January 2020 (has links)
The diploma thesis deals with the design and stress-strain analysis of a flexible coupling composed of individual rubber-textile segments. This concept allows the manufacturer to simplify and unify the production thanks to the ability to use a single segment design for multiple coupling configurations and thus leads to a reduction in costs on the part of the manufacturer. From the consumer side this allows only mechanically or chemically damaged segments to be replaced instead of the entire coupling and saves costs for the potential user. The coupling assembly is primarily designed according to the parameters of intercity electric units and locomotives, however, the individual flexible segments are not limited by this use. When designing a coupling assembly, it is necessary to place requirements primarily on the high safety of all components. The operating mode, in which the relative displacement of the input and output shafts can occur, indicates a relatively wide range of transmitted loads which, if any assembly part is improperly designed, can cause problems leading to temporary putting the entire machine/vehicle out of order. The most critical areas of the assembly include the flexible segments, the bolt connections, the strength of the hubs and the spline joint for torque transfer. Last but not least, the requirements for the non-complex production of components must be taken into account, together with the assembly and maintenance without collision of the components and the necessary tools. In order to verify the above-mentioned requirements, stress-strain analyses are performed simulating the variation of operating load conditions. Due to the reduction of hardware requirements and computational time, together with the absence of experimentally measured data of rubber and PES codes, the flexible segments were modelled at a lower level with a reduced material model favouring the tensile properties of PES cords. However, this reduction provides a more conservative approach, as this use causes higher stresses on the steel components of the assembly. Subsequently, a stress analysis of the splined joint is performed. Due to the absence of specific shaft geometry models of commercial motors and gearboxes, a parallel splines were chosen for this purpose and designed according to the specified maximum torque. The last part of the thesis is focused on verifying the tensile properties of an individual flexible segment.
50

Vliv geometrické variability dříků u existujících TEP kyčelního kloubu na deformačně - napěťové stavy / An analysis of the influence of geometric variability of total hip endoprosthesis shank on stress-strain states in the hip joint

Zýbal, Jan January 2020 (has links)
This master's thesis deals with stress-strain analysis of hip joint after total hip replacement. These stress-strain states are compared between four variable stems. A research study of available literature is presented with the focus on finite element analysis of hip joints. Basics of hip's joint anatomy is described along with total endoprostheses' variants and properties. Computational modeling was chosen as a solution method using finite element analysis. The solution was executed using ANSYS software. For each stem there was created a computational model which consists of several submodels such as model of geometry, material, contacts and loading. The assesed variables were total hip displacement, contact pressure between the head and liner, stress on each stem and strain on femur. The evaluation of femur's bone tissue was accomplished on basis of Frost's mechanostat in seven Gruen zones.

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