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Design of gear coupling
Kundýsek, Michal ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
The content of the diploma thesis is the construction of a toothed coupling for general use. The coupling was first described in order to acquaint the reader with the issue of the coupling. After approaching the issue, a practical part was created, which dealt with the conceptual design of the gear coupling. Two gear coupling designs have been developed to take into account as many customer requirements as possible. After making the model, strength calculations were created to verify the functionality of the coupling. The calculations mainly concerned important components for the operation of the clutch.
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Biomechanical study on upper extremity fixation
Rafaj, Svatomír ; Marcián, Petr (referee) ; Florian, Zdeněk (advisor)
This bachelor’s thesis deals with fixation and biomechanical aspects of fractures of the upper limb. The first part of the thesis discusses anatomy, knowledge of which is necessary for effective fixation of fractures. It describes the history of inner fixation of fractures and modern curing methods of fractures with a focus on locking compression plates. The second part of the thesis discusses strain-stress analysis of assemblage of humerus and applied locking compression. Computational model was created with the support of ANSYS Workbench 16.0 and SOLIDWORKS 2016 software. Computation was executed by finite element method using ANSYS Workbench 16.0 computational systém.
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Computational analysis the state of stress of turbine blade
Klement, Jan ; Žatko, Miroslav (referee) ; Malenovský, Eduard (advisor)
This diploma thesis continues to the Ing. Damborský work and deals with strain-stress and dynamic analysis of the steam turbine blade. This blade is part of the last row of low pressure level of steam turbine. Computational analysis has been performed in first part using FEM. After that follows a modal analysis for the blade without residual stress as well as for the blade affected by heat treatment. Main goal is to obtain whether the state of stress is in the crack initiation area is influenced by thermal treatment. This problem was solved by computational simulation in commercial software Ansys 11.0.
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Strain-stress analysis of gear coupling
Vondra, Róbert ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This thesis deals with the contact analysis study of crown gear couplings during the simulation of its working conditions. The toothed coupling transmits high torque, even when the input and output shafts are misaligned due to outside tooth shape. For this reason, it is necessary to design the gear shape correctly. The inherent use of toothed couplings results in a wide range of working speeds and load transfers. This can cause several problems, if the parameters are selected incorrectly. Among the most significant of these is the generation of vibrations during gear engagement, accompanied by noise and the excessive loading of components, such as shafts and bearings. It is not possible to completely reduce uneven running, even with knowledge of the latest trends in the field of gear development. For this reason, it is necessary to eliminate the paths where the vibrations can propagate during the design itself. Inefficient and costly experiments are often used to determine the correct shape of gear teeth. For this purpose, a computational approach to describe a contact pressure on the teeth of couplings at different misalignment and loads is proposed. The model helps to understand the composition of the contact pressure during the working mode of misalignment and its behaviour within the rotation of the gear coupling. The introductory part of thesis presents the current state of knowledge of gear couplings and a description of load distribution issues, regarding the angular misalignment, torque and friction. In the following chapter, three possible approaches to the problem are described - analytical, experimental and computational. The following work offers the introduction and creation of two different computational models, varying in different tooth shape on the hub and the sleeve. Each geometry was subjected to a different load moment, a misalignment of the hub, or the rotation of the gear coupling as a whole. The main monitored parameter was the course of contact pressure in each step, when changing the degree of misalignment or the rotation of the model. Finally, three main sets of contact pressure on the teeth are presented, in connection with the reduced pressure plotted on the toothed rings. There is derivation of results and mutual comparison of each load case. The computation approach in FEM program Ansys Workbench was used to solve the problem.
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Strain-stress analysis of spinal segment
Pánis, Vladimír ; Janíček, Přemysl (referee) ; Návrat, Tomáš (advisor)
Presented work deals with the strain-stress analysis of a spinal segment while monitoring the influence of total disk replacement Maverick on the global behaviour of the spinal segment. It also assesses the influence of this implant on the nearest upper intervertebral disk. On the basis of CT images was in the program Rhinoceros created the geometry model of spinal segment Th12-L2. The geometry model of implant was applied between vertebra L1 and L2 instead of intervertebral disk from which the whole core was removed, while in the immediate surrounding of implant the part of disk was left, which is important from the view of stability. Subsequently were in the program Ansys Workbench created finite element models for two states: - healthy (unbroken) status - status with applied implant Then the calculations for movements were realized: lateral flexion, flexion, extension, rotation. For the same movements were realized calculations of the model simulated spinal fusion of the vertebras L1-L2. Finally an influence both of methods (total disk replacement, spinal fusion) on the intervertebral disk Th12-L1 was compared.
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BIOMECHANICAL STUDY OF EXTERNAL FIXATORS APPLIED TO TIBIA
Mrázek, Michal ; Horyl, Petr (referee) ; Janíček, Přemysl (referee) ; Florian, Zdeněk (advisor)
External fixators are used in a treatment of complicated fractures and their properties have a crucial impact on treatment quality. Therefore, this thesis is concerned with a biomechanical study of a bone (tibia) with applied external fixators via strain-stress analysis and their comparison with a state of tibia without applied fixator (physiological state). After creating the volume models of geometry of tibia and seven variants of external axial fixators, the corresponding finite element method (FEM) models are created. The analysis of tibia without applied fixator and tibia with all studied fixators is made for three states of load which correspond to characteristic load states during the first stage of treatment. The strain-stress analysis is made using finite element method. Furthermore, the methods of displacement and rotation evaluation during loading are proposed. One can conclude from the results of the strain-stress analysis how the different variants of fixators prevent the displacement and rotation of the bone during the different load states and the comparisons with the physiological state of bone are made. Bone tissue loading is determined from the distribution and the values of the first and the third principal stresses. Finally, comparing the results of all variants the influence of the fixator length, the gap between the fixation elements near the fracture, the number and the setting of the fixation elements on the fixation properties is analysed.
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Analysis fitness machine with respect to frictional force and the rolling resistance
Pospíšilová, Kateřina ; Ševeček, Oldřich (referee) ; Majer, Zdeněk (advisor)
The bachelor's thesis deals with the solution of a system of bodies with NNTP bonds, i.e. pas-sive effects are included in the solution of the examples. The first part describes the theoretical foundations of statics, bonds and types of passive effects. Next, kinematic analysis, relaxation of bodies, static analysis and compilation of static balance equations are explained. This know-ledge is then applied to a specific example. In one example, three tasks are solved using the Matlab program. The template for the calculations was a real weight training machine, on which an experiment was subsequently performed to verify the calculated results. In the se-cond part of the work, it is mentioned what the finite element method is and what it is used for. Finally, a deformation analysis is performed in the Ansys program.
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