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Evaluation of elastic parameters for models of isolated cells
Krbálek, Jaroslav ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
This diploma thesis focuses on computational modeling of the cell mechanical tests. The goal of this thesis is to build a cell model and to simulate compression test on this model. If necessary, the model should be adjusted so the model reflects real cell behavior. It was created the cell model reflecting cytoplasm, nucleus, membrane and cell cytoskeleton. Cytoskeleton was modeled as tensegrity structure. After this, the pressure test was simulated on this model. The behavior of the cell model and real cell was compared using the stress force. The stress force - cell deformation curve was markedly different for the cell model and the real cell. For this reason, the cytoplasm material model was adjusted. The difference between the curves was acceptable after this modification. It was found during computations that the cytoskeleton model influence on the cell load is minimal. These results does not reflects real cell behavior, which means that the model is considered inadequate for performing stress load simulation.
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Computational modelling of noise inside cabin of aircraft VUT 100 Cobra
Prnka, Jiří ; Houfek, Lubomír (referee) ; Švancara, Pavel (advisor)
This master’s thesis deals with the computational simulation of low-frequency noise inside the cabin of small commercial airplane VUT 100 Cobra. For this low-frequncy range deterministic methods: Final Element Method (FEM) and Boundary Element Method (BEM) are used for simulation of the dynamic behaviour of the object. FEM has been used to compute eigenmodes and eigenfrequences of the structure of the aeroplane cabin and of the acoustic space inside cabin. Then response to harmonic excitation of engine represented by unit forces in place of contact has been computed. Obtained velocities on the surface of the cabin are then used as the basis for the noise calculation inside the cabin using BEM. After that effect of some construction modifications on sound level inside cabin are evaluated by computational modelling.
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Computational modelling of mechanical tests of isolated cells
Sůkal, Petr ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
The master’s thesis deals with computational modelling of mechanical testing of isolated cells, particularly of single-axle tensile test. The aim is to imitate the real deformed shape known from experiments. At first, the structure of each cell component is described and analyzed according to their significance for mechanical behavior. The outline of basic mechanical tests used for cell testing is discussed next. A structural computational model comprising all components significant for mechanical purposes is created for the modelling. Those components are nucleus, cytoplasm, cell membrane and cytoskeleton. Due to the problems with convergence the model was divided into two parts. The first one treats separately the shape of cytoskeleton and the second one treats the shape of communicating components (nucleus, cytoplasm and cell membrane). Both of those partial models succeed in reaching the deformations according to the experiments.
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Computational modelling of stress-strain states in tyres
Lavický, Ondřej ; Profant, Tomáš (referee) ; Burša, Jiří (advisor)
Work occupies computational modelling mechanical behavior elastomers and composits with rubber matrix and their utilization for compute model of tire creation. MATADOR tire 165/65 R13 Axisymetric 2D model was created in two geometric variants. For the computational modeling is applying the Finite element method (FEM). The model was in different variants distinctive grade of modeling material. At first was done inner pressure analyst impact on deformation of each of model. Then was count influence on tire load with angular velocity meanwhile with inner pressure. The impact thickness of tire protector layer on global deformation tyre casing was verified too.
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Strain-stress analysis of pathological hip joint
Stodola, Martin ; Florian, Zdeněk (referee) ; Návrat, Tomáš (advisor)
This work deals with stress-strain analysis pathological hip joint. In its introduction a research study from accessible literature sources is carried out. It covers contemporary state of scientific studies, anatomy of single components hip joint, their material properties, ways and magnitudes of loadings and most often FE model used. With use of all these informations, computational system ANSYS and gained CT scans, a model of geometry of pelvis and femur is created. Subsequently, the complete computational model o pathological hip point is compiled. On this model computational solution is executed stress-strain and sensitivity analysis. Subsequently, surgery operation is simulated on this model and it is executed stress-strain analysis. These analyses are compared with analysis of physiological hip joint.
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Stress analysis of the total hip joint endoprosthesis head under oblique loading
Janovský, Martin ; Janíček, Přemysl (referee) ; Fuis, Vladimír (advisor)
This diploma thesis is concerned with the stress analysis of the total hip joint endoprosthesis ceramic head under oblique loading. Load was obtain from experimental in vivo measurement on three patients, whereas two of them was the same weight. As input variables were use contact forces, especially knee bend and standing on one leg. Furthermore they will be considered shape deflections from ideal cone, especially circle deviation, cone deviation and cone plus circle deviation together.
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Stress analysis of the total hip joint endoprosthesis head under ISO 7206-5 loading
Varga, Jozef ; Hlavoň, Pavel (referee) ; Fuis, Vladimír (advisor)
The aim of this work is to analyse axisymetric tasks by norm ISO 7206-5, which is used to determination of static strength of ceramic heads. In the numeric analysis there will be considered form variances from nominal conicalness and circularity of stem sections i.e. possible variances caused by production. Furthermore form changes of recess inside of the head measured on real samples will be considered. All these variances from nominal values are necessary to analyse in more details, because they can participate in destruction of ceramic heads. The stem system, ceramic head and load cone (DHK) will be simulated as a 2D axisymetric task and 3D quarter symetrical task. That is why is necessary to undertake also comparing analysis of 2D and 3D tasks and compare results or eventually evaluate the error. This problem is solved using of Finite element System ANSYS 11.0.
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Literature search of possibilities of computational modelling of brain aneurysms
Lipenský, Zdeněk ; Polzer, Stanislav (referee) ; Burša, Jiří (advisor)
This bachelor thesis is focused on gathering general information about a cerebrovascular disorder called Cerebral Aneurysm (or also Brain Aneurysm) which is a medical condition consisting in an abnormal bulging outward of one of the arteries in the brain. The initial attention is given to the human cardiovascular system, a description of which is fatal for understanding the problem of brain aneurysm. The next attention is focused on the solution of eliminating the tension within the aneurysm by using knowledge gained in lectures "Flexibility and Strength II" during the sixth semester. The last chapter shows a summary of three works dealing with computational modeling of cerebral aneurysm.
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