The graduation thesis deals with invention of detailed definition of the coordinate system for Pontos system. The solution is based on suitable localization method of the point on a car body, whose coordinates are known from CAD data. First part of the thesis describes the design of adapter which determines the reference point. Software solution is presented in second part. Contribution of the work and accuracy of the method are discussed in the end.

The present work deals with simulation methods for rigid bodies and deformable bodies. In the first chapter you can find research of some methods for simulation of rigid body physics with emphasis on method used in open source physics engine Bullet. In second chapter you can find methods for simulation of deformable bodies, again with emphasis on Bullet physics engine. In last chapter model order reduction technique is presented. This method enables to reduce system of ordinary differential equations. These equations come for example from applying finite element method to partial differential equations describing motion of elastic body. The technique is studied on bar truss systems. Powered by TCPDF (www.tcpdf.org)

This diploma thesis consists of a research and a practical part. The research part summarises the problem of slopes movements. The practical part deals with the determination of the slope deformation causes, at the 76th km of the D11 motorway. Causes determination was based on laboratory tests of soil samples taken from the disrupted motorway cut, made at PřF UK soil mechanics lab. Tests of grain size composition were done, plasticity of the L 26 sample was determined and critical strength of the reconstituted L26 and L27 samples was found out in the Translational apparatus box. Soils were categorized due to the according standards and the acquired data were evaluated. In the BricsCAD software, a well arranged locality situation and the slope deformation crosscut underlayed with the geophysical ERT cut were illustrated. In the GEO5 software, slope stability models were created using the Spencer Method of Slices. The slip surface and the groundwater level during the disruption were determined. The practical part also covers a proposal of a remediation appropriate for this deformation and it's modelling in GEO5. For the remediation, the slope stability level is determined. The work is based on the specialized literature, articles, research reports and standards. Powered by TCPDF (www.tcpdf.org)

Title: Numerical modelling of vocal folds Author: Mgr. Bc. Jakub Michálek Department: Geophysics Department Supervisor: RNDr. Jakub Velímský, Ph. D., Geophysics Department Abstract: I created a 2D model of vocal fold oscillations driven by interaction with fluid flow (FSI model). I used the theory of finite strains of the structure. The flow was modelled as a viscous incompressible fluid. The numerical problem was solved by the finite element method (FEM) with the arbitrary Lagrangian- Eulerian (ALE) method. The model shows the regime before phonation without the contact of the vocal folds and the states that directly lead to the contact of the vocal folds. I compared the time dependence of the quantities measured at sensors attached to the folds. I measured the frequency characteristics and compared the results with the modal analysis. Consequently, I calculated a parametric study of the dependence of the oscillations on the inlet air velocity, the original distance of the vocal folds and the elasticity of the vocal folds. The parametric study confirms that a sufficient increase of the inlet air velocity and a sufficient constriction of the glottis lead to the phonation onset. The parametric study also shows that changing elastic parameters has a similar effect on the spectrum for both the FSI model and the modal...

New technologies of components assembling in car and aircraft industries and requests on improved mechanical and corrosion properties of metallic materials in the packing industry activate the utilization of highly innovative and unconventional manufacturing processes. There are only a limited number of processing, that retain the original material thickness and in an appropriate manner modify material properties. These are different types of annealing, severe plastic deformation methods or combination of both. In recent years constrained groove pressing (CGP) was devoloped with this method the grain size can be reduced from tens of micrometers to sub-micrometers. The present work is focused on a study of evolution of microstructure and mechanical properties of two alloys based on EN AW 3003 after CGP deformation and subsequent annealing.

Title: Study of ultrafine-grained materials prepared with different methods of severe plastic deformation Author: RNDr. Tomáš Krajňák Department: Department of Physics of Materials, Faculty of Mathematics and Physics, Charles University in Prague Supervisor: Doc. RNDr. Kristián Máthis, PhD., Department of Physics of Materials, Faculty of Mathematics and Physics, Charles University in Prague Abstract: Interstitial free steel with ultrafine-grained (UFG) structure was prepared by high-pressure torsion (HPT). The development of the microstructure as a function of the number of HPT turns was studied at the centre, half-radius and periphery of the HPT-processed disks by X-ray line profile analysis (XLPA), positron annihilation spectroscopy (PAS) and electron microscopy. The dislocation densities and the dislocation cell sizes determined by XLPA were found to be in good agreement with those obtained by PAS. The evolution of the dislocation density, the dislocation cell and grain sizes, the vacancy cluster size, as well as the high-angle grain boundary (HAGB) fraction was determined as a function of the equivalent strain. It was found that first the dislocation density saturated, then the dislocation cell size reached its minimum value and finally the grain size got saturated. For very high strains after the...

This thesis is dealing with analysis of landslide on the eastern hillside of the Mužský hill, which lies on the Příhrazská plošina Plateau in Český ráj. Příhrazská plošina Plateau belongs to areas, where landslides occur very often and it is well known for a destructive landslide at Dneboh village in 1926. Landslide under the Mužský hill originated on hillside of a Tertiary volcano, which penetrated Cretaceous sandstones and claystones. That distinguishes it from other landslides in the area. Geophysical method of electrical resistivity tomography was used for finding landslides slip surface. Due to small resistivity contrast between landslide mass and underlying claystones, it was not able to identify slip surface with high certainty. The results show only some indications of it. The geophysical exploration however, proved that the landslide mass is overlaying originally exposed sandstone blocks in the accumulation part of the landslide. The whole area of the landslide was mapped into engineering geology map of slope stability at 1:2000 scale with the help of GPS. Slope map on the basis of digital model terrain acquired from LiDAR measurements was used, as a basis of new map. This slope map provided more information about older landslides around examined landslide. From results of the mapping was...

Title: Microstructure and mechanical properties of lightweight structural AZ31 alloy prepared by twin-roll casting method Author: Mariia Zimina Abstract: Microstructure of AZ31 twin-roll cast magnesium alloy was studied using light optical, electron and atomic force microscopy. The effect of annealing temperature on the microstructure was tested. Mechanical properties of a thin magnesium strip were investigated by means of microhardness tests and tensile tests at a relatively low strain rate 10-3 s-1 . Results show that the ductility of the twin roll cast strip increases with increasing deformation temperature, however, a remarkable decrease was observed at about 200 řC. This effect appears also in a conventionally cast ingot of a master alloy and is caused by a change of a deformation mode occurring at this temperature. Moreover, the effect of severe plastic deformation on the microstructure and mechanical properties was studied. Equal channel angular pressing was applied on magnesium strip samples and lead to a significant grain refinement accompanied by an unfavorable strengthening of the initial basal texture, which is effectively suppressed by a subsequent annealing. A constrained groove pressing was for the first time successfully applied on AZ31 twin-roll cast strip leading to an increase of...

The aim of this diploma thesis is to investigate microstructure and thermal stability of ultra fine grained magnesium alloys. The thesis first summarises methods using plastic deformation in order to achieve ultra fine grained structure that are used to process metals. Then experimental methods employed in the experimental part including microhardness testing, scanning electron microscopy and positron annihilation spectroscopy are described. Brief summary of previous research on MgZnY alloys strengthened by quasicrystalline phases and Mg22Gd alloys is given. Finally, results of experimental investigation of MgZnY alloys with various Zn/Y ratios and Mg22Gd alloy are discussed. These results suggest that presence of phases in MgZnY alloys depend on Zn/Y ratio, hardness of these alloys depends on Zn content and that rapid cooling of MgZnY alloys annealed at 500 řC lead to significant increase in volume fraction of quasicrystalline icosahedral phase. In the second section of the experimental part thermal behaviour of Mg22Gd alloy is investigated. Furthermore, formation of GdH2 particles in Mg22Gd is examined and attributed to reaction of hydrogen decomposed from water vapour with gadolinium in areas rich in gadolinium. Finally, significant hardening of Mg22Gd alloy processed by high pressure torsion has been...

The diploma thesis is fucused on scanning deformations of wood which has high value of humidity and defects in its structure. The experiment was carried out on standard trial corpuscles. Beech, oak and poplar were chosen as experimental timber species. The influence of high humidity and defects on mechanic qualities and deformations on this tiber species was examined and studied. The aim of thesis is to find out mutual difference and compare the results between defornations measured by standardly used conventional methods and contactless digital image correlation (DIC) and also verify of application of this optical method. The thesis includes also numerical model.