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Evaluation of stress and deformation of a bimetallic beam under changed temperature
Jurkovič, Vítězslav ; Horníková, Jana (referee) ; Burša, Jiří (advisor)
This bachelor’s thesis deals with stress-strain analysis of a selected bimetallic strip. First, a literature search is carried out on used bimetallic strips, including introduction of used materials and criteria for their selection. Next, an analytical calculation of free deformation of the strip at the chosen temperature is performed using rod assumptions. The following is a comparison with the results obtained using finite element method in the Ansys Workbench system. The analysis of the same strip with limited deformation is then performed using the finite element method. In this way, a stress analysis of the complete deformation constraint is performed first, including verification of the results using substitute of the deformation boundary by a force one. The following is a deformation analysis when the deformation is constrained by the selected valve spring with existing clearance, including the determination of the compression of spring. The outputs of this thesis are the results of the free deformation of strip at given temperature change, the analysis of the resulting stresses in strip due to the constrained deformation and the calculation of compression of valve spring at temperature changes.
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Engineering optimization of the pressing process of the turbo molecular pump rotor
Baklík, Jiří ; Čekán, Václav (referee) ; Vosynek, Petr (advisor)
This thesis deals with the issue of press fitted joints and the optimization of the rotor pressing process of the mechanical turbomolecular pump nEXT300T. The press fitted assembly consists of three main parts (blade discs, hollow shaft, main shaft). The blade discs are press-fitted onto the hollow shaft, then this assembly is press fitted onto the main shaft. The optimization was performed by computational modeling based on the finite element method, using ANSYS Mechanical 2024 R1. The pressing process has been optimized to reduce production costs. The assembling process is more expensive due to liquid nitrogen, which is currently used for cooling the press fitted parts. Design of the pressing temperatures was carried out. For heating a temperature of 130 °C was determined. For cooling a temperature of-65 °C was chosen, this can be achieved using an industrial freezer. Due to the change in pressing temperatures, tolerance fields of the components were designed to ensure that the assembly can be assembled and that the press joint will not be lost under operating load. For the connection between the blade discs and the hollow shaft, a radial interference of 0,0585-0,0695 mm is required for functionality. For the connection between the hollow shaft and the main shaft, a radial interference range of 0,01-0,02 mm is functional.
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Design of the connection of the friction pad and the outer ring of the clutch bearing
Kopytko, Alexandr ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This thesis focuses on the design of the connection between the friction pad and the outer ring of the clutch release bearing. During the assembly of the friction pad, occasional damage occurs, leading to material degradation and production delays. Given the wide range of polyamides used in this application, the research includes an overview of these materials, their modifications, and methods for joining plastic with metal. The friction pad represents a further step in the improvement of the clutch mechanism; thus, the research also covers the single-plate friction clutch and its development. The connection between the friction pad and the bearing is implemented using clips that ensure a firm mechanical bond. The analysis employs the finite element method (FEM) in Ansys Workbench, utilizing 3D geometry from Creo Parametric. Based on the stress-strain analysis, design modifications of the clip connection were proposed. The outcome of the thesis includes two new models of the friction pad and their modifications, with clip dimensions approaching the manufacturability limits. The conclusion of the thesis compares the newly developed models with the commercially available design, proposing manufacturability and assembly procedures. This comprehensive approach ensures that the new design solution is not only technically feasible but also can be economically viable and practically applicable in industrial production.
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A review study of dental mini-implants
Pernický, Vojtěch ; Hrubanová, Anna (referee) ; Marcián, Petr (advisor)
This thesis focuses on the study of dental mini-implants, which are becoming a popular choice for replacing missing teeth and retaining overdentures. The insertion of mini-implants is a less invasive procedure that minimizes damage to bone tissue, which shortens the patient's recovery time. One of the key advantages is the possibility of immediate loading of the implant. However, the smaller diameter of these implants means a smaller surface area for osseointegration, which can negatively affect their stability and functionality. This thesis deals with the analysis of deformation and stress states by using computational modeling. The results of this analysis are compared with standard implants to evaluate the mechanical behaviour of mini-implants and their interaction with bone tissue. Based on the results of the analysis, it can be said that the diameter of the implant significantly influences its deformation-stress states.
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Stress-strain analysis of the LKDS800 frame
Tománek, Jiří ; Vlk, Miloš (referee) ; Vosynek, Petr (advisor)
This diploma thesis deals with frame of the two-point crank press LKDS800, which was designed by company ŽĎAS a.s. Frame is welded construction creating the base of the press which has mass approximately 90 tonnes. Aim of this study was to perform strain-stress analysis of the frame. From obtained results perform optimization of mass this frame leading to reduce material costs and machining. In the process is frame loaded by nominal forces from the shearing process, under its own weight and inertia forces caused by moving components. As a result of the dynamic loading in welded joints there are risks of fatigue fracture. The manufacturer of the press is required to find the most loaded welded joint and it to assess the fatigue life.
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Computational tool for a stress-strain analysis of the mechanically loaded circular and annular plate
Dohnal, Jakub ; Majer, Zdeněk (referee) ; Ševeček, Oldřich (advisor)
The bachelor's thesis primarily deals with the creation of a computational tool for stress-strain analysis of rotationally symmetric circular and intercircular plates. The commercial software MATLAB and its component APP DESIGNER were used for this purpose. The program uses analytical relationships of general solid mechanics to solve differential equations for several types of plates and loads. Part of the bachelor thesis is also a parametric study comparing the outputs of analytical and numerical model based on the finite element method, aimed at identifying the practical application of the analytical solution and its accuracy for a particular case of the plate.
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Research study of mandible fracture reconstructions from a biomechanical standpoint
Semerák, Jaroslav ; Florian, Zdeněk (referee) ; Marcián, Petr (advisor)
This thesis deals with the treatment of mandibular fractures using splints and fixators. The topic was the development of a detailed research study based on available literature. The work also indicates basic anatomy of the surveyed area and nowadays the most commonly used materials. Then, the stress-strain analysis of the system broken mandible with angular stable fixation was performed. Stress-strain analysis solution was realized by computational modeling, in use of the finite element method in Ansys Workbench 16.2. The work is described in detail the creation of computational model system and its subsequent solutions.
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Strength design of the aircraft spur
Profota, Martin ; Vosynek, Petr (referee) ; Vrbka, Jan (advisor)
This master thesis deals with computational stress-strain analysis of the tailskid of airplane L410 NG with main focus firstly the check current design of the tailskid and then the design another design solution with the able to absorb as much as possible the deformation energy. Solution of this problem is performed using computational modeling utilizing numerical simulation of quasi-static and crash deformation load of the tailskid with using explicit Finite Element Method (FEM) in program ABAQUS v6.14. After the introduction with problem situation and tailskid assembly introductory part is devoted to the research study of various designs of the tailskid for different types of airplanes. There follows these theoretical general principles of thin-walled structures and buckling of them. Before the creating of the computational model itself, the explicit form of the Finite Element Method is better described. The conclusion of this thesis deals with the mutual comparison of the most advantageous design variants of the tailskid and the selection of the most suitable one of them for the airplane L410 NG.
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Biomechanical Study of Hand
Krpalek, David ; Janíček, Přemysl (referee) ; Horyl, Petr (referee) ; Florian, Zdeněk (advisor)
This work deals with issue of human wrist and appropriate total wrist implant allowing a restoration of hand mobility approaching physiological condition after traumatic and degenerative diseases. Treating these diseases are very complex. These issues including a biological and medical issues. To determine the appropriate treatment method and select right total wrist implant is important to know the behavior the human wrist at all stages in terms of medical and biomechanical. For this reason, it was developed a biomechanical study including computation model of human wrist allowing solution of strain and stress of hand in physiological and pathological conditions and condition after total wrist implant. The frost remodeling of bone tissue was used for analysis of human wrist bone tissues and bone tissues after application of total wrist implant RE-MOTION™ Total Wrist.
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