|
|
Research study of mechanical properties of cranial tissue
Wojtek, Lukáš ; Valášek, Jiří (referee) ; Marcián, Petr (advisor)
This bachelor thesis deals with the problematics of determining mechanical properties of cranial bone tissue. In this thesis a search study associated with an experimental determination of mechanical properties of bone tissues is executed. A brief history and progress of imaging methods and their importance of computation modelling are introduced. There are descriptions of histomorfometric parameters describing a structure of bone tissue at the micro level, ways of their computation and their impact on mechanical properties of bone tissue. Practical part of the thesis is focused on processing micro-CT images of cranial bone as well as analysing histomorfometric parameters (BV/TV, TbTh, TbSp) and subsequently stress strain analysis of selected sections of cranial bone tissue. Resulting Young´s modulus of elasticity of bone tissue [MPa] are compared with results from experiments from literature.
|
|
|
Three dimensional force sensor
Černý, Hynek ; Krejčí, Petr (referee) ; Houfek, Lubomír (advisor)
The bachelor’s thesis dealt with the design of a force sensor, which was supposed to do measurements of forces in three axes independently. The another required output of the work was creation of drawings. The design and optimalization of shape and dimensions of the sensor was made mainly in program called ANSYS. An important part of the work was the expression of final relations for the calculation of forces both analytically using simple elastic strength and the numerical finite element method. The last part of the work was an experimental measurement, which was supposed to verify accuracy of both methods for forces expression and also correct functionality of the sensor.
|
|
|
Stress-strain analysis of mandible with applied fixator due to the missing bone tissue
Fňukal, Jan ; Valášek, Jiří (referee) ; Marcián, Petr (advisor)
This thesis deals with the fixation of lower jaw with bone tissue defect using commercially produced fixator. Large defects of bone tissue are mainly caused due to the removal of bone tissue affected by tumor. These topics have been researched on the basis of the literature. Subsequently, stress strain analysis of the lower jaw with the applied fixation plate was performed. This analysis was solved by using computational modeling with variational approach, ie the finite element method. The work also describes in detail the procedure of creating model of geometry, model of material, model of boundary conditions and loads with subsequent solution of several computational models. The stress strain analysis was done for lower jaw with varying size of the removed bone tissue with applied reconstruction plate made of CP-Ti Grade 4 and for the lower jaw with the plate, which is made of -Ti-Mo. Finally, the influence of the mechanical properties of the callus during formation of new bone tissue (callus healing) on the stress and deformation of the solved system was evaluated.
|
|
|
Stress, deformation and safety analysis of the tandem bicycle frame
Profota, Martin ; Dobeš, Martin (referee) ; Vrbka, Jan (advisor)
Purpose of this work was the evaluation safety and pliancy of the frame structure tandem bicycle using method of basic elasticity with the help of the deformation and stress analysis. After introduction material and geometry of the frame tandem bicycle introductory part is focused on theoretical basis of calculation like beam assumptions, definition the beam, limit states, Sentence of Castigliano and Saint Venant's Principle. Before commencement actual analytical solution the spatial task was transferred to plane task and used model was simplified. Calculation related to two load states differing by way of load of frame tandem bicycle. For each load modes comparison with numerical solution by FEM was enabled. Mathematical software like Mathcad 14 and Maple 13 were used to analytical calculation. Check was performed by numerical solution in program ANSYS Workbench 14.5.
|
|
|
Biomechanical Studies of Facial Bone
Valášek, Jiří ; Janíček, Přemysl (referee) ; Horyl, Petr (referee) ; Florian, Zdeněk (advisor)
Presented work deals with Biomechanical study of the facial skeleton. This work is focused on the fixation of the mandible after removal of a tumor from affected bone tissue. The aim of the work is to perform biomechanical study of the facial skeleton with subsequent detailed stress strain analysis of two mandible implants designed and manufactured for specific patients. The geometry model of mandible used for design of mandible implants and used for computational modelling has been obtained on the basis of CT data of two patients. A Theoretical-Clinical sub-study that deals with the comparison the CT data processing which is necessary for creating the model of geometry is a part of the thesis. Two models of mandible with applied mandible implant have been created for two specific patients with tumorous mandible bone tissue. Stress strain analysis has been performed for these two models. Results of the stress strain analysis of two models of mandibles with mandible implants are presented in the final chapters of the thesis. Findings of the biomechanical study have been published and applied in clinical practice.
|
|
|
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.
|
|
|
Stress-strain analysis of a chosen fire extinguisher
Češek, Jakub ; Petruška, Jindřich (referee) ; Novák, Kamil (advisor)
Bachelor’s thesis deals with stress-strain analysis of chosen extinguisher. Within this thesis, different types of closures are summarized and their influence in stress state is thoroughly analyzed. The stress-strain analysis is solved by using momentum shell theory as well as membrane shell theory. At the end of this thesis numerical solutions by using Finite Elements Method (FEM) is performed in Ansys software. All results are compared in conclusion of the thesis.
|
|
|
Stress-strain analysis of chosen climbing rung
Hložek, Jiří ; Vaculka, Miroslav (referee) ; Novák, Kamil (advisor)
This bachelor thesis deals with a stress-strain analysis of chosen climbing rung. The thesis is divided into four main parts. The first part of the thesis reviews three-dimensional frames (grates) and their possible solution. The second part includes analytical solution of chosen, idealized climbing rung by using Castigliano´s theorem. The third part includes numerical solution by using finite element method performed in ANSYS software. Finally, the last part summarizes results which are also thoroughly discussed.
|
|
|
Strain Stress Study of Burch-Schneider Split
Řehák, Kamil ; Horyl, Petr (referee) ; Janíček, Přemysl (referee) ; Florian, Zdeněk (advisor)
This thesis deals with problems of the hip endoprosthetics area, namely total endoprosthesis (TEP) with Burch-Schneider (BS) split, in which there are many problems in clinical practice. The hip joint load depends on the patient weight and the performed activity. Sedentary job, little exercise, a lot of stress or poor eating habits and overweight associated with it affect negatively hip joint. Increasing hip joint wear and its pain in movement is necessary in several cases to be solved by a surgical procedure in which TEP is applied. When selecting and subsequently applying individual TEP, it is important to pay attention to creating conditions which will allow good fixation. In case of worse mechanical properties of bone tissue, it is very problematic to ensure stability of the implant. Based on several classifications which assess the degree of hip joint damage, it is possible to select a suitable TEP. The BS split, on which this work is focused, is dominantly used in cases of large defects in the acetabulum area. The use of this cage allows to bridgelarge defects and create a new centre of rotation of the hip. Knowledge of the mechanical properties of hip bone tissue can significantly affect the prediction of BS split damage. For this purpose, it was necessary to perform a biomechanical study, which is focused on the influence of worse mechanical properties of bone tissue on BS split failure. The computational modelling using finite element method implemented in the ANSY S software was used for the solution, which enables to solve the mechanical interaction between bone tissue and TEP with BS split. Due to the absence of bone tissue data before application of TEP with BS split, the variants before application of TEP and after application of resurfacing and standard TEP were solved. All variants were solved with the material properties of bone tissue that were determined based on CT images. In addition, all variants were solved for the case of degraded mechanical properties. Based on the numerical simulations results and the Mechanostat hypothesis, a bone tissue analysis of the hip joint was performed before and after application of TEP and TEP with BS split. The results show the influence of the computational model level, which considers the distribution of bone tissue through the inhomogeneous model of the material. Therefore, the degraded mechanical properties have a major impact on the stability and strain of the BS split, particularly in the cranial part of the acetabulum.
|
|
|
Strain and stress analysis of the femur with distraction intramedullary nail
Konvalinka, Jan ; Marcián, Petr (referee) ; Florian, Zdeněk (advisor)
This master's thesis is focused on determination and analysis of stress and strain in femur with distraction intramedullary nail for treating leg length discrepancy with the method of distraction osteogenesis. Thesis is mainly focused on states after distraction when the callus consolidates. Problem of determining stress and strain is solved by computational modeling using FEM. Detailed description of modeling is included in this thesis, complicated 3D geometry of bone was acquired from segmentation of CT images. Computational model is solve with 4 different types of callus geometry and also material properties of callus are varied. The influence on stress and strain when the middle distal screw is not applied is also analyzed.
|
guest ::
