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Solution methods of composite beams
Jamal, Dany ; Zídek,, Rostislav (referee) ; Brdečko, Luděk (advisor)
Solutions of composite beams encounter some specific problems, such as shrinkage and creep of concrete, cracking of concrete and plasticity of steel, partial interaction of elements or history of erection and loading process. These factors and others affect the distribution of internal forces along the beam, the distribution of stresses along the cross-section and also stiffness and deflection of beams. The goal is to describe and compare methods for analysis of composite steel and concrete beams by more simplified approaches allowed by Eurocode with more advanced techniques. The studies will be carried out on the simply supported and continuous beams designed with respect to Eurocode 1, 2, 3 and 4.
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Analysis of cracking of aluminium profiles during bending process
Kalivoda, Ondřej ; Šebek, František (referee) ; Vosynek, Petr (advisor)
The presented thesis was created in cooperation with Siemens, s.r.o. and deals with the analysis of the bending of aluminium sheets. These products are used as conductors of electrical energy. The problem happened when the bending angle was 90 ° when there was a violation outside of the bend. The aim of the thesis is to verify whether the bend is correctly designed using analytical and empirical relations and the finite element method. Because of the requirement for running numerical simulation on one of the freely available software the Salome Meca program environment was used. The results of numerical simulation did not confirm that the violation should occur. In deeper analysis appeared doubts whether it is possible to correctly evaluated result only by data from tensile test. In the final part, there are recommended some experiments which would be necessary for the correct calibration of the ductil fracture criteria.
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Analysis of plastic bearability of plates
Rozsypalová, Veronika ; Hradil, Petr (referee) ; Němec, Ivan (advisor)
The subject of this thesis is analysis of the plastic bearability of plates. The first part is dedicated to a description of pertinent theories. It is primarily a theory of material nonlinearity and plasticity, including a description of plasticity models, which are commonly used in engineering analysis. Next is the hinted theory of geometric nonlinearity and discusses the key principles of limit plastic bearability of plates. This thesis includes ultimate strength calculations of plates of selected shapes, their solution by both, a manual calculation and using computational software. The obtained values are subsequently evaluated. The appendices contain the procedures for modelling in the computational programs RFEM and ANSYS.
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A simulation of closed die forging using finite element method
Nytra, Michal ; Šebek, František (referee) ; Kubík, Petr (advisor)
Tato diplomová práce se zabývá výpočtovým modelováním zápustkového kování, které patří do metod objemového tváření zatepla. Cílem je změnit běžnou praxi tvorby výpočtových modelů ve specializovaných softwarech na bázi metody konečných prvků (MKP) a sestavit výpočtový model v MKP softwaru Abaqus. Pro výpočet jsou zde použity deformační varianta MKP a explicitní algoritmus. Řešenou součástí je ozubené kolo automobilové převodovky. V rámci práce je vytvořena rešerše z oblasti objemového tváření včetně specializovaných programů pro simulace procesů tváření. Dále jsou v práci uvedeny všechny konstitutivní vztahy pro popis elasto-plastického modelu materiálu s tvárným porušením. Následuje teorie přenosu tepla, jsou popsány všechny způsoby jeho realizace s jejich matematickými formulacemi včetně metod řešení. Klíčovou je kapitola popisující postup tvorby výpočtového modelu v softwaru Abaqus od tvorby geometrie až po okrajové podmínky. Následuje analýza dosažených výsledků a práce je zakončena výhledem na možné pokračování v tomto tématu.
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The influence of the magnitude of normal forces on nonlinear seismic analysis
Holiš, Ondřej ; Lang, Rostislav (referee) ; Vlk, Zbyněk (advisor)
The thesis is focused on studying the influence of the magnitude of normal forces and loads on the nonlinear dynamic analysis. Pushover method and nonlinear time history analysis were used to solve these problems. A number of numerical models with different nonlinearities and progressively increasing loads have been developed. The results were then compiled into graphs and tables for comparison. RFEM 5, RFEM 6 and a program in Python were used for the calculations.
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Research plasticity of foundry sands
Macků, Martin ; Křístek, Jiří (referee) ; Rusín, Karel (advisor)
The subject of this thesis was to develop a comprehensive methodology for evaluating the plasticity of molding sand. This study was focused on four types of mixtures that are used in the foundry industry. For the evaluation of plasticity was important to provide an indicator of the deformation ability, calculation of deformation and logarithmic transformation for compression. Plasticity methodology was applied in this work only on the pressure effect. Studies of this issue can have a great influence on the production of correct forms due to the ability to withstand tension without breaking form.
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Stress - strain analysis and creep assessment of the thick-walled tubular structures.
Zouhar, Michal ; Petruška, Jindřich (referee) ; Hlavoň, Pavel (advisor)
This thesis deals with the stress-strain analysis of thick-walled pipe parts. The dimension series (characterized by the D/d ratio) of three components are solved, then a direct tube, a torus with constant wall thickness (arcus) and a torus with variable wall thickness (bend). At first, the internal pressure amount, when a fully plastic state for these components is created, is solved. The amount of the limit pressure is determined analytically, numerically and by appropriate normative relations. The results and stress diagrams of individual solutions are mutually compared. Furthermore, these components are solved in the creep and are exposed to the maximum allowable normative internal pressure for 200,000 hours according to the standard – the operating time of components. The place of the maximum equivalent creep strain and the place of the maximum equivalent stress is examined. In these places the principal stresses are depicted depending on the D/d ratio. The results and stress diagrams of individual dimension series are mutually compared. From the available literary sources the condition of the limit state reach is chosen, according to which the evaluation of the limit state reach for individual components is carried out.
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Organic architecture and contemporary residential living
Čábelková Nahorniaková, Marcela ; Kyselka, Mojmír (referee) ; Budkeová, Branislava (referee) ; Glosová, Dagmar (referee) ; Menšíková, Naděžda (advisor)
Organic architecture is often used term especially in connection with the daring and experimental form. The exact definition or division is still missing. The founder of modern organic architecture is to be generally considered as Frank Loyd Wright. He was the man who created organic architecture and also made first definition in the early twentieth century, when formulating new architectural styles. Dissertation deals with insufficiently described problem of organic architecture. The main focus is on contemporary production of residential organic architecture in Central Europe. Especially on the particular realizations in Hungary, Czech Republic, Slovak Republic, Austria, Germany and Poland. Beside detail description of European realizations, the dissertation deals also with foundations of organic architecture in U.S.A. and important realizations here. Modern organic architecture primarily originated in the United States of America. The work presents most important contemporary realizations and architects creating resident living organic architecture in other countries around the world in order to complete the overview. The objective of dissertation was describing newest trends in designing buildings for living. Find position of organic architecture and give reasons for it´s increasing popularity, spread and necessity for new development in architecture according to the new trends. Organic architecture is an alternative way of contemporary residential living. It´s popularity is growing in last years in response to the development of modern technologies and materials, the need to protect our natural resources and also to the increasing negatives of globalization and to denial of local traditions and regional specificities. Aspects of organic forms were divided into three main groups according to their main characteristics: form, harmony and sustainable development. Another objective was find location of contemporary organic residential architecture in Czech Republic and abroad. It is rather spread all over the world than concentrated on certain places. Therefore I selected countries that are richer than the others on the occurrence of organic buildings. The objective was also to address architects, specialists, public and especially university teachers of architecture and students themselves. Communication with them was mainly connected with grant project in 2010. The theme of grant project was contemporary organic architecture in residential living. There were lectures about contemporary organic architecture and exhibition on the theme: Contemporary living organic architecture. The publication of the catalog was published under the title: Contemporary organic houses - Europe. I had the opportunity to visit a number of organic family houses abroad. Specifically houses in Slovakia, Hungary and Germany. Results of survey, which was realized by questions to owners and authors of chosen buildings, are included in dissertation. The mail results of dissertation are - make a detail review of organic architecture in residential living - define trends in contemporary organic architecture and residential living - obtain and process answers from owners and authors of chosen buildings within survey - analysis of organic house ( houses) in city planning and landscape - publication of catalogue focused on organic contemporary European houses - article about contemporary organic architecture and residential living will be published in 2012 on archiweb page
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Computational analysis of leveling of square cross section rods
Šebek, František ; Návrat, Tomáš (referee) ; Petruška, Jindřich (advisor)
Current requirements in mechanical engineering require more accurate operations and more efficient technologies. The aim of this thesis is the analysis of the leveling of square rods. The main problem is the setting of the leveling machine for the specified material and geometric data so that the initially curved material, which passes through alternatively positioned offset rollers, is leveled as much as possible. The main factor in the leveling process is the plastification of the material used for the redistribution of the residual stress. Based on existing theo-retical knowledge in this field, programs are set up to simulate the passing of the rod through the leveling machine. Further, modifications leading to the improvement of the whole process are presented. Finally, there is a verification of the results which is made independently of the submitted solution and processed by the finite element method.
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