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Design and analysis of membrane roof of a stadium.
Lang, Rostislav ; Kytýr,, Jií (referee) ; Němec, Ivan (advisor)
This diploma thesis deals with problem of design and calculation of membrane structure of stadium roof. This is a complex engineering problem, which includes many partial problems: finding of initial form of membrane, statically and architecturally suitable arrangement of catenaries, economical solution of boundary conditions (foundations). All components affect each other and cannot be dealt without mutual coordination. It always greatly depends on the experience and intuition of engineer who design such structure. Task which cannot be resolved according to the theory of the first order. Equilibrium forces on the deformed structure, which in many projected structures gives satisfactory results, did not correspond to reality. It is therefore necessary to consider equilibrium of forces on the deformed structure according to the theory of large deformations. Diploma thesis was entered with regard to the intention of the companies Ing. Software Dlubal s.r.o. and FEM consulting s.r.o., working together to develop software RFEM. These companies plan to complement this program system with a module MEMBRANE for searching of initial shapes of membrane structures. This work is a contribution to the creation of this module.
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Static Analysis of Textile Structures
Husáriková, Natália ; Gratza, Roman (referee) ; Kytýr, Jiří (advisor)
This work deals with the design and calculation of membrane structure for shelter placed above selected ground plan. The hyperbolic paraboloid was chosen as most optimal shape. Subsequently, three different sub-studies were conducted. In the first study, influence of mesh density on a finite element calculation model was studied. Second study deal with the effect of the geometry changes of the computational model. In the third study, deformations and tensions of membrane structure in relation to material formation calculation model was studied. For the static solution of those selected variant, structural analysis software RFEM and RF-FORM-FINDING add-on module was used. Geometric nonlinear solution was applied in the calculation.
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Study of impact of a transport vehicle into a structure.
Sychrová, Šárka ; Salajka, Vlastislav (referee) ; Němec, Ivan (advisor)
Master's thesis deals with the analysis of the impact of transport vehicle on a building structure. Transport vehicle is represented by an airliner and building structure is represented by a containment of a nuclear power plant. The aim of thesis was to explore the possibility of numerical simulation of an impact of transport vehicle on a building structure utilizing the RFEM program and evaluation of the damage extent.
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Static and dynamic analysis of Prestressed bridge structure
Hokeš, Filip ; Nečas, Radim (referee) ; Kala, Jiří (advisor)
The main objective of the thesis is to perform static and dynamic analysis of prestressed concrete bridge structures in computational system ANSYS. For the analysis was chosen footbridge over the river Svratka in Brno. In relation to this topic are solved various types of modeling prestress at a finite element level. Before analyzing the footbridge is analyzed in detail the static system and the corresponding final geometry of the structure. Knowledge of the functioning of the static system is used to build the computational model of the structure, on which is subsequently performed static and dynamic analysis.
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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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Simulation of Idiofonic System
Múčka, Martin ; Keršner, Zbyněk (referee) ; Frantík, Petr (advisor)
The thesis deals with dynamic simulation of real bell behavior over time. The model is created according to principles of physical discretization as a spring in the FyDiK3D software. In order for the model to be declared as relevant, it is necessary to prove the behavior of the structures used in the elementary tasks of the mechanics. It shows the correlation between the stiffness of normal and diagonal springs. Describes how to use software import tools to create a model. The resulting model approaches its real bell behavior.
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Qualitative study of beam finite elements
Martinásková, Magdalena ; Němec,, Ivan (referee) ; Nevařil, Aleš (advisor)
The issues were selected that have been expected to induce complications in modelling or calculations. These were solved in commercial softare RFEM, Scia, Axis and ANSYS using the FEM. The problems include geometric nonlinearities or address buckling or torsion. The basic theory and the software solutions are presented. For each task there are stated the parameters of calculation for individual programs, in more complex cases the way of assembling the model and solution steps are also described. The results obtained are compared to theoretical analytically obtained solution.
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Implicit and Explicit Method in nonlinear Dynamics
Vaněčková, Adéla ; Hradil, Petr (referee) ; Němec, Ivan (advisor)
The final thesis „Explicit and Implicit methods in nonlinear dynamics“ deals with the issue of geometrical and physical nonlinear analysis of structures exposed to seismic loading by the methods of direct integration of equations of motion. Solution by the explicit and the implicit method is compared for three material models. While the differences between the results of the explicit method and the implicit Newmark method are small as expected, the differences are substantial between the results of different material models. However, these differences are explained and they are in full concordance with the theoretical assumptions for the pertinent material models. The conclusion of the final thesis is check of correctness of the results of the new module of the program system RFEM for both tested numerical methods and all three analyzed material models. (linear elastic, plastic Drucker-Prager and the Mazars damage model). With sufficient precision of results, both explicit and implicit numerical methods showed to be suitable for seismic analysis. The implicit method can provide several times faster calculation than the explicit one, but the determination of the optimal time step is problematic and time consuming, so the suitability of use of both methods for seismic analysis is comparable.
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Lateral-torsional buckling of beams - analysis of specific cases
Piják, Jiří ; Barnat, Jan (referee) ; Bajer, Miroslav (advisor)
Thesis deals with flexural-lateral buckling of asymmetric cross sections, especially assessment according to ČSN EN 1993-1-1. Models are based on bar, shell and solid finite element method. Assessment of software Scia Engineer and RFEM are analysed in bar model. Plate and volume model uses shell and solid elements and initial imperfections. Computing is geometrically nonlinear. Correspondence of bar and plate model is studied. Optimal amplitude is suggested. Simple beam loaded with continuous line loading is taken as an example.
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