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Low-temperature evolution of granulites in the Moldanubian Zone of the southern Bohemian Massif
Kořínková, Dagmar ; Svojtka, Martin (advisor) ; Matějka, Dobroslav (referee)
The Variscan orogeny occured during Devonian to Carboniferous convergence between peri- Gondwanan crustal segments and the northern European plate (Baltica). Due to the convergence, Bohemian Massif represents the easternmost and largest exposure in the European Variscan belt. In the southern part of the Bohemian Massif, the Moldanubian Zone consists of several crustal segments with different polyphase tectonometamorphic histories. Moldanubian Zone is considered to represent the Variscan orogenic root, being surrounded by rigid and less metamorphosed blocks to the NW and SE. Structurally highest unit of the Moldanubian Zone is the Gföhl Unit, which is built by heterogeneous assemblage of high-pressure crustal and upper-mantle rocks comprising granulites, peridotites, pyroxenites and eclogites exhumed during Variscan orogeny. The apatite samples studied in my diploma thesis come from different types of granulites from the Blanský les granulite massif (BLGM) located SW of the town of České Budějovice. BLGM is the largest granulite body of the southern Bohemian Massif, is an integral part of the Gföhl Unit. BLGM consists mainly of calc-alkaline high-pressure felsic garnet ± kyanite granulites, which enclose up to several kilometers long lenses of ultrabasic rocks, numerous boudins of mafic...
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Welding of turbine rotor materials.
Richter, Tomáš ; Slováček, Marek (referee) ; Daněk, Ladislav (advisor)
Master’s thesis titled Welding of turbine rotor materials discusses evaluation of welding parameters by numerical simulation in software SYSWELD and Visual - WELD. Base material 23 CrMoNiWV 8-8 is welded by submerged arc welding technology. Used flux is F 26G and electrode is flux-cored wire TOPCORE 838 B. Material structures, hardness, values of residual stresses and distortion of weldment for this process are calculated by using the numerical analysis.
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Defects and properties of heavy castings
Sobotka, Petr ; Carbol, Zdeněk (referee) ; Záděra, Antonín (advisor)
A diploma thesis was objected to a figure analyzing and a figure interpretation of ingot processing. The described figures were obtained from samples which were taking from feeder-heads of ingot of lower ram, produced in Vitkovice Machinery Group. The thesis was focused on ingot solidification and segregation processes which were associated with this procedure. The figures obtained from numeric simulation of ingot solidification in defined places were analyzed using statistic method – linear regression, as well as linear regression was used for evaluation of explored samples, their chemical compositions and mechanical properties. In conclusion all acquired results were summarized.
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Problem of the crack terminating at the bimaterial interface
Svoboda, Miroslav ; Ševeček, Oldřich (referee) ; Profant, Tomáš (advisor)
The objective of this diploma thesis is the stress-strain analysis of the crack terminating at the orthotropic bi-material interface suggested as the plane problem of the linear fracture mechanics. The first part is engaged in basic relations of the linear fracture mechanics. The second part is focused on the singularity exponent evaluation for the crack impinging and generally inclined with respect to the bi-material interface. It follows the determination of the generalized stress intensity factors applying the analytical-numerical approach represented by the finite element analysis. The last part of this work is focused on the testing of algorithms applied to the specific crack and bi-material interface configurations. A conclusion discusses the influence of the bi-material mechanical properties and the angel of the crack inclination to the obtained numerical results.
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Comparison of strains determined by finite element method and by optical measurement system
Zajíček, Vít ; Hlavoň, Pavel (referee) ; Vlk, Miloš (advisor)
This thesis focuses on the comparison of numerical simulation and optical measurement of deformation of the turbinehousing made by Honeywell company. The numerical calculation performed by finite element method to simulate transient thermal load on the measured entity. Numerical result of the strain state of the body caused by temperature gradients. To verify the simulation is used an experimental digital correlation method VIC-3D. The thesis also mentioned the theoretical foundations of digital correlation methods and thermal analysis.
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Simulation of indoor environment in a car cabin
Tuka, Ján ; Pokorný, Jan (referee) ; Fišer, Jan (advisor)
The thesis deals with the evaluation of indoor environment cab passenger car, with a focus on thermal comfort of passengers. The theoretical part contains the fundamentals of heat transfer, analysis of the aspects affecting human thermal comfort and its assessment methods. A brief description of the ventilation and air conditioning systems used in passenger cars is mentioned. The practical part includes numerical simulations of indoor environment, in selected driving modes and at different climatic conditions. Results of simulations lead to evaluation the status of the internal environment in terms of thermal comfort.
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Modelování proudění s volnou hladinou pomocí VOF
Chára, Zdeněk ; Hoření, Bohumír
The contribution deals with an application of the method VOF ("Volume of Fluid" implemented in Fluent software) on free surface flow over obstacles placed on a channel bottom. The numerical results are compared with experimental observations of flows over two square cross section cylinders and over broad crest weir.
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Study of crack growing through an interface of two different materials based on analysis of crack profile in the vicinity of crack tip
Bareš, Pavel
Paper describes a numerical study of a crack penetrating the interface between two different elastic materials. The stability conditions of a crack terminating at the interface are formulated. The method introduces herein for these purposes is based on the assumption that the crack will start to propagate through the interface into the second material M2 when the shape of the crack face in the immediate vicinity of the crack tip will correspond to that in the same sample but made of purely homogeneous material M2. The numerical calculations are performed on the sample with surface protective layer under the small scale yielding conditions. The resulting critical stresses are compared with those obtained by other approaches. All results are in qualitative agreement. This method should be applicable in cases of larger crack-tip plastic deformations as well, where so far known methods are not able. All numerical calculations are performed by finite element method (system ANSYS).
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Analysis of Circular Bars Shearing Process
Dohnalová, Eva ; Hůlka, Jiří (referee) ; Foret, Rudolf (advisor)
In these days customers require a high quality as well as precision of products together with a cost that is as low possible. The cost of products can be reduced in a way of batch production. Implementation of the batch production requires a detailed plan of a technological process to avoid making depreciated products or series of products. A software package can be used to simulate the technological process of shearing to avoid difficulties of particular technological process. This bachelor paper contains analysis of technological process of shearing of circular section rods. The results of the analysis are going to be included in FEM simulations. The effect of the technological process of shearing on material was determined by optical and scanning electron microscopy method. The microhardness measurement was used to analyse the deformation hardening of the examinated material.
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