The diploma thesis focuses on analysis of mechanism of chip formation during machining of titan alloys. Application of titan alloys in metal-working and engineering industry is currently very significant topic. The mechanism of titan chip formation is dissimilar to steel and its foundation plays an important role in optimization of cutting process.

The master thesis deals with a stress-strain analysis of the front crash structure of a race car by using the finite element method. The structure is loaded by an impact loading. This type of analysis belongs to the transient analysis so the explicit formulation of the finite element method is used. The LS-DYNA software was used for calculations. The goal of this thesis is to express the influence of the crash structure to the change of the car's kinetic energy as well as the amount of absorbed energy in case of frontal impact.

This master’s thesis presents an overview of the basic forces acting on the vehicle, the basic methods of analysis of accident, collection of data used in the analysis of accidents, an overview of the basic performance criteria and thresholds used in the homologation test of occupant protection in a frontal impact, used crash tests, homologation tests and specifications for these tests. Attention is paid to Euro NCAP crash tests and to homologation tests of vehicles Skoda Octavia with aim to try to compare them with selected accidents in terms of depth and character deformation and evaluate findings comparision.

The main subject of this master thesis is the computational modeling of stress-strain analysis of the loaded front part of Toyota Yaris from the year 2010 using an explicit finite element method (FEM). The aim of this thesis is the assessment of resistance of the front part of the car (longeron) at the impact stress. This thesis describes the selection, editing, and creation of the computational model of longeron and simulation of the barrier collision. The objective of the thesis is to use a real vehicle, suggest modified longerons to be implemented in it, test various shape and material versions of the longeron and make their comparison.

To, jak se bude implantát chovat v lebce, je velmi důležitým faktorem, který ovlivňuje jeho funkci. K ovlivnění dochází především vnějšími silami a nitrolebečním tlakem. Tato zatížení mohou způsobit pohyb implantátu a poškození živých tkání. Tato práce shrnuje poznatky a analýzy, týkající se rekonstrukce poranění lebky. Srovnání implantátů z různých materiálů a fixátorů je založené na napěťově-deformační analýze implantátu, zatíženého vnějšími silami a nitrolebečním tlakem.

Theoretical part PhD thesis describes bending of sheets especially with a small bend radius and the distribution of deformation and describes the parameters of bent sheet. As the test sheets were treated by cataphoretic coating is this method described together with pretreatment of sheet. The practical part is focused on the principle multi-jet plasma system and treatment of the steel surface and examines the bent surfaces of the steel sheets with different variants of applying the coating. Selected samples are bent on the multifunction graduated bending jig and subjected to the Erichsen test and deduced results using plasma system and without the use of plasma system. In the experimental part were examined samples treated by multi-jet plasma system and subsequently bent on the multifunction graduated bending jig. Compares the results of individual experiments in system steel – base coat – plasma – topcoat. And also compares mutual combinations of various kinds of modifying the surfaces of steel samples with different coatings. Selected samples were tested for tensile test and the results were processed from this test. For selected samples was calculated hardening exponent. Another experiment consists in applying a circle at equal samples and subsequently the samples were bent under a defined radius and were determined tensile and compressive deformation. Samples of sheets were then embedded in the resin and then examined under a microscope, where they were divided into several categories and was determined optimal composition multi-jet plasma system for selected samples and the specific coatings on sheet plate with a maximum adhesion of the coating to the steel base. Selected measured values were subjected statistical control.

In the present work the deformation behaviour of magnesium-based alloy AZ31 which was produced by horizontal continual casting is investigated. Samples with two different orientations are deformed in tension and compression at strain rate of 10-3 s-1 in temperature range of 20 řC to 300 řC. Simultaneously, the acoustic emission is recorded and studied with focused on mechanical twinning. The mechanisms of plastic deformation of material and anisotropy between tension and compression are discussed. Dependence of deformation behaviour on temperature is analyzed. The microstructure of original and deformed material is also studied by means of optical microscopy.

Title: Study of cooperative dislocation phenomena in solids by the acoustic emis- sion technique Author: Michal KNAPEK Department: Department of Physics of Materials Supervisor: doc. RNDr. František Chmelík, CSc., Department of Physics of Materials Abstract: Plastic deformation of micron-scale crystalline materials differs con- siderably from bulk specimens, as it is characterized by random strain bursts. Three categories of metallic samples were investigated in this thesis: micron- scale copper micropillars with varied geometries, submillimeter-scale aluminum microwires, and aluminum and aluminum-magnesium salt-replicated foams. Very precise fabrication methods and sensitive measurement set-ups consisting of uni- axial compression and tensile tests with concurrent acoustic emission (AE) record- ing were developed. These fine methods allowed for investigations of effects re- lated to plastic deformation at micrometer scales, i.e. the dislocation dynamics associated with the stress drops. Size effects in plastic deformation, as well as clear correlations between the stress drops and the AE events, were found in mi- crosamples, confirming that dislocation avalanches are indeed responsible for the stochastic character of deformation processes also at microscales. Open-cell pure aluminum and aluminum-magnesium...

In geosciences modelling is rather quickly developing discipline. Statistical modelling of landslide susceptibility is relatively more traditional approach. Nevertheless, more complicated statistical methods are being developed and applied on larger areas. This development is caused especially by increasing computational capacity and software. This diploma thesis summarises existing statistical landslide susceptibility modelling approaches. In the following part, several landslide susceptibility models were created for the area of Czechia. These models were created using logistic regression, naive Bayes and artificial neural network (ANN). Additionally, two more models were created using expert driven approach. All models were made using thirteen conditioning factors, i.e.elevation, slope, engineering geological regions, climatic areas, mean annual precipitation, topographic wetness index (TWI), aspect, orogenetic class, distance from confirmed fault, distance from watercourse, internal relief, land cover and slope shape. Models driven by statistical approach were created using Orange software. Landslide inventories that were used for construction of all models are based on two databases: "Registr svahových nestabilit" and "Registr sesuvů-Geofond". Using validation by SRC, PRC and ROC curves...

The thesis aimed to study the impact of manufacturing and assembly technology, the valve bolt fitted to diesel high pressure pump CP3 in the Bosch, which has been found to leak. As experimental material was chosen heat treated bolts M16x1,5 made of material 12 050th. Groups of samples were produced in two ranges hardness. Experimental determination of the optimum range of hardness was assessed on the basis of the results of the process of the screw and set the value of plastic deformation of the sealing surfaces of the parts. Experimental section also deals with the analysis of bearing surfaces on the pump and the components, after the screw process. To some extent, is observed as surface treatment