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Computational simulation of cross-roll leveling of rods
Benešovský, Marek ; Vrbka, Jan (referee) ; Petruška, Jindřich (advisor)
Final thesis describes two variants of computational models to simulate cross-roll leveling of rods, which are based on the Lagrangian approach to describe the continuum. Implementation of both variants was performed in ANSYS software, and their main difference lies in the choice of the type of elements for the discretization. An integral part of this thesis is the description of the principle, which is an evaluation of the curvature of the rod after completion of the simulation leveling. In the other part of the work are presented the results, which are then compared with realized experiment and simulation algorithm for cross-roll leveling based on the Euler approach. The final part is dedicated to the optimal settings of the leveller.
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Space mission design
Koziel, David ; Navrátil, Jan (referee) ; Zikmund, Pavel (advisor)
In this work, there are basic laws and knowledge relating to space flights into an orbit around the Earth. Also, there are instructions for beginners, who want to work with the GMAT program (General Mission Analysis Tool), which is the program used for designing space missions. In the final part of the work, there is also a use of the program demonstrated on a specific mission of a satellite (CubeSat) into the Geostationary Earth Orbit. In this section, there is a described method of work, individual relevant functions of the program and possibilities, and a way of work in it. Finally, graphical and data outputs of the simulation are evaluated. Therefore, the output of the work is complex characteristics of the basics of problems of space mission design and a brief GMAT software guide, which could be used in the future to teach.
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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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The Influence of Passive Safety Features During Vehicle Collisions with Pedestrians
Mrázek, Jan ; Vémola, Aleš (referee) ; Tokař, Stanislav (advisor)
This thesis deals with the influence of passive safety features during vehicle collisions with pedestrians. The first part focuses on introducing the basic components of active and passive vehicle safety. The second part deals with construction and usage of modern components of passive safety during vehicle collisions with pedestrians. A comparing situation model of vehicle collisions with pedestrian is introduced in the third part for which a simulation programme has been used. At the close of this part there is a result synthesis of these model situations. The last part deals with the possibility of increasing pedestrian safety.
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Application of Fluid-structure Interaction on Oscillating Human Vocal Folds
Meisner, Patrik ; Švancara, Pavel (referee) ; Hájek, Petr (advisor)
The presented thesis is involved in the biomechanics of phonation. The aim of the thesis is to set a fluid-structure interaction between the vocal folds and air flow when the pressure from lungs reaches the physiological values. In the expected outcome the self-oscillating vocal folds should be observable with characteristics shape-shift from convergent to divergent. In theory part of the thesis is described Anatomy of the vocal tract, physiology of the human phonation, research of computational simulations, experiments and visualisation methods are described in the theory part of the thesis. In the second part, setup of computational simulation with the finite element method is presented. Besides of the fluid-structure interaction the acoustical model is set. Achieved results are presented and compared to the results in literature. Displacements are evaluated from the structural model and pressures, velocities and flow velocities are evaluated from fluid model, so as acoustics results.
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Simulation of the sound transfer via human ear
Hájek, Petr ; Švancara, Pavel (referee) ; Pellant, Karel (advisor)
The presented thesis concerns the biomechanics of hearing. The main aim of this work is the determination of so called corrections which allow for the comparison of synthetic audiograms and measured audiograms. With these corrections we attempt to overcome the discrepancy that exists between the computational modelling and audiological measurement. The discrepancy lies in a fact that the computational modelling usually simulates the sound coming from a free eld to the external auditory canal, while audiological measurement is realized by audiological headphones, whether the auditory system is healthy or injured. Then corrections adjust the computational model so that the obtained result is comparable to audiological measurement. In this work is also addressed the influence of stapes kinematics to the excitation of basilar membrane. The movement of stapes consists of piston-like movement and rocking movement. The computational simulation shows which movement is more signicant for the excitation of basilar membrane and how this effect can be used in otosurgery, in particular, for type IV of tympanoplasty.
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Computational simulation of leveling of non-circular rods
Stráník, Radim ; Návrat, Tomáš (referee) ; Petruška, Jindřich (advisor)
This bachelor’s thesis illustrates the principle of straightening rolled through long table roll straightening machines using repeated plastic deformation, based on Eulerian description of the material flow. Thesis describes the program on computational simulation process straightening rods and extends it an easy to use input module for entering non-circular cross-section rods. At the end of the discussion also introduces the optimal settings for all input parameters to achieve best results.
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Computational Simulations in Automotive Safety
Krkoška, Kamil ; Svída, David (referee) ; Ramík, Pavel (advisor)
The goal of this bachelor thesis is to build up a compact overview of recent development in automotive safety, concrete methods and results reached in this branch. Here are briefly described solutions for improvement of active and passive safety and next is explained testing of these systems in crash tests and assessment of these tests by using biomechanical limits. Attention is also given to the usage and benefit of computational simulations. Next are described procedures of simulations and also software used for these simulations. Then there are mentioned examples of successful applications of computational simulations.
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Influence of setting and configuration of straightening machine on results of simulation of cross-roll straightening
Ščerba, Bořek ; Petruška, Jindřich (referee) ; Návrat, Tomáš (advisor)
Analytical methods or implicit finite element method (FEM) with beam elements to model straightened bar were used to analyze straightening process in multi-staggered cross-roll straighteners up to now. These are effective but require certain simplifications. Aim of this thesis is to create an explicit FEM model allowing usage of solid elements for circular bar without disproportional increase of computational time. This may lead to deeper understanding of the straightening process. The model is to be verified using straightening tables and then used to quantify influence of rollers configuration on results of the straightening process.
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Dynamic characteristics obtained from solution of simple vocal folds models
Kubíček, Radek ; Švancara, Pavel (referee) ; Hájek, Petr (advisor)
Bachelor’s thesis concerns the biomechanics of voice and its aim is to obtain dynamic characteristics of simple analytical and numerical vocal folds models. Thesis includes main theories of voice production and thorough analysis of the widest used computational models. Essential is an anatomical and physiological introduction including basic pathologies. Behaviour of computational models mentioned in the bibliographic research is demonstrated by the dynamics characteristics gained by modal analysis and by the solid mechanics equation solution. Eigenfrequencies come under range from literature. The aim of thesis is comparison of analytical and numerical solution and particular computational models.
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