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Porovnání spolehlivostních metod při stanovení návrhové únosnosti mostu / Comparison of reliability methods in determining the design resistance of a bridgeŠplíchal, Bohumil January 2022 (has links)
This thesis deals with the topic of assessing the design load-bearing capacity of a prestressed concrete railway bridge structure. The determination of the structure’s load-bearing capacity is carried out using probabilistic nonlinear analysis using the finite element method. Load-bearing capacity is determined for the recommended limit states. A fully probabilistic approach is compared to other reliability semi-probabilistic methods, such as the ECoV method according to Červenka and Eigen ECoV, and deterministic methods, like partial safety factor method, or the method according to ČSN EN 1992-2. The results are evaluated in terms of accuracy, consistency and time consumption for each method.
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Statické řešení nosné konstrukce knihovny / Static analysis of the supporting structure of the libraryŽůrek, Jan January 2022 (has links)
Diploma thesis deals with design and assessment of a ceiling of a library in Ostrava. The solved beamed ceiling is above the third floor. Static analysis of the structure was calculated by Scia Engineer 20 software. Two variants of ceiling was calculated. Thesis then focuses on prestressed ceiling.
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Autosalon v Olomouci / Car show room in OlomoucMudrák, Štěpán January 2022 (has links)
The subject of this diploma thesis is structural design of a car showroom building in Olomouc. The layout dimensions are 16 x 37 m, the roof is designed as a 5° slope half span roof with cantilever hanging of 6 m. Roof layout dimensions are therefore 22 x 37 m. The object is designed as a two – storey building with two levels of second floor. Maximum height of the structure is about 9,0 m. The design is based on a study of two materiál variants – timber and steel structure. More suitable variant was chosen and following drawings, structural design report and technical report were processed. Main structural system is designed as a one rigid corner column – girder connection, 6 m axis dimensions. Main structural material is a glued laminated timber, completed with coniferous timber and steel elements. The roofing is supported by rafters which are connected to the main roof truss. Bearing element of floors is a Novatop Element structural systém. The spatial rigidity of structure is ensured by steel stiffeners. Structural analysis was carried out by finite element method in software Scia Engineer 21, where the design of the basic elements for ultimate limit state and serviceability limit state was made. Connection design was processed manuály and with software Idea Statica and Hilti Engineering Suite.
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Analýza napjatosti a porušení ve zkušebních tělesech používaných pro určování lomově-mechanických parametrů kvazikřehkých materiálů / Analysis of stress state and failure in test specimens used for determination of fracture-mechanical parameters of quasi-brittle materialsHolušová, Táňa January 2012 (has links)
The thesis is focused on a test on determination of the fracture-mechanical parameters of quasi-brittle materials, especially concrete. What is referred to as the wedge-splitting test is considered, for which a variety of shapes of notched specimen can be used. This work is exclusively focused on the cylinder-shaped specimen of diameter 150 mm and breadth of 100 mm. The test is performed virtually using Atena 2D FEM software. Progress of failure is observed during loading of the specimen for various notch lengths. The amount of energy released for the development the failure outside of the tested cross-sectional area (weakened by the notch) is quantified and the size of the fracture process zone is investigated. The described analysis is performed for several material sets witch differ in cohesive properties of the quasi-brittle material expressed via the so-called characteristic length. Suitable proportions of the test specimen are sought, in order to avoid the failure and thus also the energy dissipation outside of the specimen ligament area during the experimental tests, which shall lead to more accurate estimates of fracture-mechanical parameters of the tested material.
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Vliv technické a přírodní seizmicity na stavební konstrukce se zaměřením na konstrukce ze zdicích materiálů / Influence of technical and natural seismicity on building structures with focus on structures of masonry materialsČada, Zdeněk January 2014 (has links)
The dissertation deals with selected issues in the field of the calculation of the response of building structures which are excited with dynamic non-stationary displacement loading of its ground. Seismic load has been assumed. Procedures, how to work with seismic records with respect to the accuracy of dynamic calculations, how to modify the response spectrum to ensure the reliability, how to generate synthetic accelerogram requiring more accurate response, are recommended. Synthetic akcelerogram has been generated by own approaching, which has been used as the excitation function in the experimental seismic testing of autoclaved concrete brick building in model scale. Response values of motion in the measured points of the experiment were compared with the linear and nonlinear dynamic calculations by using the finite element method models. Different levels of detail of the numerical models have been used. The shear wall behaviour has been modelled by using constitutive models with brittle failure as well as using of non-linear interaction interface with possible delamination between the masonry bricks. The behaviour of the mathematical model of wall systems has been calibrated with respect to the measured data at shear wall experiments in real and model scale of walls.
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VLIV PARAMETRŮ VYSOKOTLAKÉHO OSTŘIKU NA KVALITU ODOKUJENÍ / EFFECT OF HIGH PRESSURE WATER BEAM PARAMETERS ON QUALITY OF DESCALED SURFACEVavrečka, Lukáš January 2011 (has links)
This work is focussed on hydraulic descaling of hot surfaces. Hydraulic descaling is a process when layers of oxides are removed from hot steel surfaces during continuous rolling. High pressure water beam is used. Quality of descaled surfaces is important for final quality of rolled product. Insufficient descaling causes drop of final quality, degradation of rolls and lost of yields. High-pressure water beam has two effects on a scale layer. The first effect is mechanical caused by impact pressure. The second one is a relatively intensive thermal shock depending on a set of parameters (water pressure, nozzle type, distance from the surface, inclination angle, speed of product moving). There are a lot of theories about principles of scales removing. Main task of this work is to make it clear which theory is acceptable and which is just ,,theory”. For this purpose mathematical modelling and experimental work were used. In experimental part, three types of experimental measurement were done. First one, measurement of dynamical effect of water beam – impact pressure. Second one, measurement of temperature drop when a product is passing under the nozzle. Measured data (temperatures) from this measurement are evaluated with inverse task and heat transfer coefficient is obtained. And the third experimental measurement is simulation of whole process of descaling. Quality of descaled surfaces is valuated according to amount of remained oxide scales. Data from firs and second experimental measurement are used as boundary conditions for mathematical modelling. For mathematical simulations, FEM (finite element method) system ANSYS was used. Obtained data from experimental measurement were applied on 2D and 3D models of basic steel material with layer of scale. Influence of theses data on final temperature, stress and strain fields were observed.
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Komplexní teoretická analýza metody sloupku pro zjišťování zbytkových napětí / Comprehesive Theoeretical Analysis of Ring-Core Method for Residual Stress DeterminationCivín, Adam January 2012 (has links)
Comprehensive analysis of the ringcore method used for the determination of the residual stresses in mechanical components is presented in this thesis. Principles, advantages, disadvantages and applicability of this semidestructive experimental method are discussed too. At the same time the ringcore method is compared with the hole drilling method, which is used more frequently. All aspects of the ringcore method are analyzed by the finite element method. FE simulations, performed on the universal numerical model, verified principles of the integral method and the incremental strain method. FE simulations also provided basic information for the uncertainty analysis, which significantly affects the accuracy of the residual stress measurement. The main goal, which the present work deals with, is to create a global overview of all ringcore methods´ aspects elaborated in a clear and complex form.
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Ověření možnosti využití tahové deformace při Hopkinsonově testu / Verification of the Exploitation Possibility of Tensile Strain during the Hopkinson´s TestDohnal, Ivo January 2014 (has links)
The PhD thesis deals with the possibility of performing dynamic tensile tests. For this purpose, Split Hopkinson Pressure Bar Test (hereinafter SHPBT) is used. The basic construction of SHPBT device is designed to perform dynamic compression tests on materials (metals, plastics, and ceramics). The obtained results are deformation stress – strain and strain rate – strain dependences. SHPBT is capable of testing materials at high strain rates up to 10^2 – 10^3 s-1. It was created a special device for dynamic tensile tests of materials at high strain rates. The created device uses the basic construction of SHPBT. The special device is used for testing flat specimens with 2 mm thickness. It was recognized by the Industrial Property Office of the Czech Republic as a utility model with number 23703. The specimens used for dynamic tensile testing were made of austenitic stainless steel (WNr. 1.4301) with 2 mm thickness. The verification of created device was carried out by numerical simulation. The numerical simulation was performed by ANSYS LS – Dyna software.
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Analýza chování kořene kotvy v jemnozrnných zeminách / Behavior analysis of a ground anchor fixed length in fine grained soilsChalmovský, Juraj January 2016 (has links)
Ground anchors represent an important structural element in the area of ground engineering. Despite an extensive usage of these elements, their design is usually performed using simple empirical and semi-empirical methods. An application of these procedures brings to the design a number of simplifying assumptions. The goal of the dissertation is to refine the computational design of ground anchors, analysis and quantification of selected factors significantly affecting their load displacement behavior. Firstly, the finite element method is applied. Two novel constitutive models are used: Multilaminate Constitutive Model for Stiff Soils (Schädlich, 2012) involving post peak shear softening of overconsolidated cohesive soils and Shotcrete Model (Schädlich, 2014) involving tension softening after tensile strength is reached. First constitutive model was used in order to simulate progressive decrease of skin friction along the anchor fixed length. Second constitutive model was applied for the grout material. In the next step, experimental program including several anchor load tests was carried out. The goal of the experimental program was to confirm conclusions from numerical studies and to obtain relevant data for further back – analysis. A newly developed application, in which all the findings from numerical computations and experimental measurements are incorporated, is described afterwards. The application is based on the use of so-called load-transfer functions. The program verification was conducted through series of back analysis of investigation anchor load tests realized on four different construction sites in two different types of fine-grained soils. The verification of the application is followed by series of parametric studies in which an influence of input parameters values is analyzed. Dissertation is concluded by the summarization of the most important findings.
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Nosná konstrukce vícepodlažní budovy / Structure of multi-storey buildingAchillesová, Jana Unknown Date (has links)
This diploma thesis deals with the project of the structure of ferroconcrete multi-storey building. Selected parts for assessment are point-supported slab over the 1st floor, inside column, external and internal wall in the 1st floor. Finite Element Method in software Dlubal RFEM 5.23 was selected for the analysis. Another part of the thesis is the project of dimensions of foundations that are dealt with as deep foundations in accordance with engineering-geological survey.
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