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Buckling Length of Steel Columns in Frame Structures Stressed by Fire
Červenka, Roman
Fire resistance is crucial for load-bearing structures. However, current rules in structural Eurocodes may not cover all fire design situations. In EN 1993-1-2, fire design rules exist only for braced steel frames, treating each floor as a separate fire section. Unbraced frames lack specific fire design rules and use regular temperature design buckling lengths. This article presents an analysis of the behaviour of columns in braced and unbraced frames and compares it with the procedures of some other authors.
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Stability Analysis of Thin-Walled Cold-Formed Sigma Profiles Using the Finite Strip Method
Venzara, Mikuláš
The stability analysis of cold-formed thin-walled profiles often benefits from the effective application of the finite strip method. Among the software tools based on this method is the CUFSM program. This article provides an overview of the principles of the finite strip method and the use of the CUFSM program for conducting parametric studies. Specially, the focus is on investigating the influence of the geometry of web intermediate stiffeners in Sigma-sections on the buckling capacity of flanges with edge stiffeners during distortional buckling. The parametric studies are automated through appropriate modifications of the CUFSM program source code.
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Methods of Static Buckling Analysis
Svoboda, Filip ; Eliáš, Jan (referee) ; Frantík, Petr (advisor)
The aim of this theses is to create application, which is able to calculate buckling load of structure made from 1D bar elements, using finite element method. introduction is devoted to basic principles of buckling and derivation of necessary formulas. Then are described all operations and numerical methods needed for the application. At the and is in detail analyzed few structures and results are compared with known solutions or with other applications.
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Finding kinematic quantities of a mechanism and a structural analysis of its members after blockage
Zvozil, Ondrej ; Vosynek, Petr (referee) ; Fuis, Vladimír (advisor)
Diplomová práca, ktorá vznikla v spolupráci so spoločnosťou AUFEER DESIGN (AFD), sa zaoberá analýzou konkrétneho stieračového mechanizmu automobilu. Najprv je uvedená stručná história stieračov. Stieracie sústavy sú potom rozdelené podľa ich usporiadania a spôsobu pohonu. V nasledujúcej kapitole je formulovaná problémová situácia, problém a systém podstatných veličín. Kinematické veličiny kľúčových bodov mechanizmu sú určené analytickým aj numerickým prístupom. Výpočtový model pre kinematickú analýzu je vyvinutý v Matlabe a SimMechanics. Ďalšia časť je venovaná vytváraniu konečno-prvkového modelu v programe ANSA. Všetky deformačne-napäťové analýzy sú vykonané v programe Abaqus. Prvá z nich je parametrická štúdia, ktorá odhaľuje kritické polohy mechanizmu z hľadiska tlakového namáhania určitých súčastí. Mechanizmus v kritických polohách je potom zaťažovaný so zablokovanými ramenami stieračov. Nakoniec sú urobené lineárne analýzy straty vzpernej stability súčastí, u ktorých môže nastať, nasledované nelineárnymi analýzami so zahrnutými imperfekciami.
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Construction of equipment for thin walled L-profiles instability testing
Polčák, Marek ; Vaněk, František (referee) ; Horák, Marek (advisor)
Bachelor’s thesis deals with the loss of stability of axially loaded thin-walled aluminium profi-les, which make up an important part in the aircraft structures. The loss of their stability is tes-ted by the compression test, which is used to determine the buckling load. Compression test may be influenced by many factors, which are related to the fixing to the testing machine. The aim of the thesis is to design a fixture, which would fix a specimen to the testing machine and improve the results of the test.
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Strength design of the aircraft spur
Profota, Martin ; Vosynek, Petr (referee) ; Vrbka, Jan (advisor)
This master thesis deals with computational stress-strain analysis of the tailskid of airplane L410 NG with main focus firstly the check current design of the tailskid and then the design another design solution with the able to absorb as much as possible the deformation energy. Solution of this problem is performed using computational modeling utilizing numerical simulation of quasi-static and crash deformation load of the tailskid with using explicit Finite Element Method (FEM) in program ABAQUS v6.14. After the introduction with problem situation and tailskid assembly introductory part is devoted to the research study of various designs of the tailskid for different types of airplanes. There follows these theoretical general principles of thin-walled structures and buckling of them. Before the creating of the computational model itself, the explicit form of the Finite Element Method is better described. The conclusion of this thesis deals with the mutual comparison of the most advantageous design variants of the tailskid and the selection of the most suitable one of them for the airplane L410 NG.
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Stress-strain analysis of the railway bridge in Zahrádky near Česká Lípa
Abdul moghni, Abdul rahman ; Vosynek, Petr (referee) ; Fuis, Vladimír (advisor)
Cílem této bakalářské práce je využití deformačně napěťové analýzy na Železniční most v Zahrádkách u České Lípy. Konstrukce mostu byla zjednodušena a vymodelována jako nosníková konstrukce. První část bakalářské práce byla věnována získávání vstupních dat a základních informacích z technické dokumentace mostu. V nosníkovém modelu bylo využito několik zjednodušení. První model považujeme za staticky neurčitý, zatímco druhý jako staticky určitou konstrukci. Každý model tedy obsahuje zátěž z důvodu vlastní váhy a zatížení způsobeno projíždějícím vlakem. Z důvodu objemnosti rovnic, využíváme k výpočtu software Maple. Zkontrolovali jsme i mezní stav vzpěru pro oba modely, avšak jsme uvažovali pouze zatížení vlastní váhou a zatížení způsobeno vlakem. Po získání analytických dat bylo důležité tyto výsledky ověřit. Toto bylo docíleno využitím metody konečných prvku za pomocí programu Ansys. Veškeré výpočty byly provedeny pro 2D modely. Jediná výjimka je numerická sekce, kde byl přidán 3D model za účelem porovnání s 2D modelem.
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Problems of Reliability of Steel Members Sensitive to Imperfections
Nezbedová, Anna ; Lehký, David (referee) ; Kala, Zdeněk (advisor)
This thesis deals with the problems of reliability of steel members sensitive to imperfections. Formulas for nonlinear analysis of compressed and bended members are derived. For compressed elements, there is described the issue of buckling, for bended elements it is lateral-torsional buckling. Then a statistical analysis of reliability of these problems is performed and also comparison with the approach described in Eurocode 3.
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Steel Structure of Observation Tower
Klimeš, Pavel ; Šmak, Milan (referee) ; Hron, Lukáš (advisor)
The bachelor thesis concerns with the design and static analysis of the lookout steel construction, which has the height of 25 m and is situated in the Žabčice location. The technical report and drawings are included in the thesis as well. The aim of the thesis was to determine the lookout total load (including permanent, live and climate loads), its implementation in the computer software SCIA Engineer 2012.0 and to perform the stress analysis of selected rods, joints and anchorages by means of the manual calculation. The author of the thesis focused on the climatic load due to wind and ice accretion, which was determined with the use of two approaches according to standards ČSN EN 1991-1-4, ČSN EN 1993-3-1 a ČSN ISO 12494. Both the approaches were evaluated and for the less favorable one the static analysis was carried out.
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Study of Precision of the Stability Analysis
Sotulář, Jiří ; Pilgr, Milan (referee) ; Hron, Lukáš (advisor)
The thesis deals with the precision of the stability analysis of the pressed member. The loss of stability of the bukling is determinate by using several metods, which are compared each other. The thesis is partitioned into three parts that works together. The first part deals with the theory of analysis of the buckling stability. Here is described the gradual solution of analytical analysis for real beam and here is described the final compared for ideal, imperfekt and real beam too. It is also short solved buckling by using software. In the second part is compared by using computing systems and anylitical analysis for several basic buckling systems. The results of the compared are summarised in the final graphs and tables for each solved element and systems. In the third part are designed and static checked load-bearing element of steel storage hall. The buckling beams are checked by using findings from the previous analysis.
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