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Development of algorithm and pertinent program mogule for statical and dynamical analysis of cables on pulleys
Štekbauer, Hynek ; Hradil, Petr (referee) ; Němec, Ivan (advisor)
The goal of this master thesis is to develop an algorithm for solving cables on pulleys, which would be more efficient and accurate than existing algorithm used in software RFEM. This algorithm was integrated to the program for static and dynamic analysis of structures, in the form of particular program module. This work also contains examples of using this algorithm. The comparison of expected results with outcomes from the program is presented. The suitability for common practise is examined based on this comparison. The examples showed that the new algorithm for solving of cables on pulleys is more powerful and more accurate than existing solutions and most likely does not has equivalent competition.
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Verification of nonlinear material models of concrete
Král, Petr ; Němec, Ivan (referee) ; Hradil, Petr (advisor)
Diploma thesis is focused on the description of the parameters of nonlinear material models of concrete, which are implemented in a computational system LS-DYNA, interacting with performance of nonlinear test calculations in system LS-DYNA on selected problems, which are formed mainly by simulations of tests of mechanical and physical properties of concrete in uniaxial compressive and tensile on cylinders with applying different boundary conditions and by simulation of bending slab, with subsequent comparison of some results of test calculations with results of the experiment. The thesis includes creation of appropriate geometric models of selected problems, meshing of these geometric models, description of parameters and application of nonlinear material models of concrete on selected problems, application of loads and boundary conditions on selected problems and performance of nonlinear calculations in a computational system LS-DYNA. Evaluation of results is made on the basis of stress-strain diagrams and load-displacement diagrams based on nonlinear calculations taking into account strain rate effects and on the basis of hysteresis curves based on nonlinear calculations in case of application of cyclic loading on selected problems. Verification of nonlinear material models of concrete is made on the basis of comparison of some results of test calculations with results obtained from the experiment.
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Statical and dynamical analysis of glass structures
Trojanová, Lenka ; Křiváková, Jarmila (referee) ; Němec, Ivan (advisor)
Glass and the glass elements found thein way into almou all area sof human aktivity thanks to technological advances of the last 20 years. The are of construction i sof course no exeption, quite the contrary. These days it is difficult to imagine building without the glass element, whether it is a part of the interior or exterior. Yet the theory on this issue is at a very low level in the Czech Republic. The content of my work is static and dynamic analysis of structures of glass, when it is applied in practice, it will save money.
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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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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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Comparison of various methods for nonlinear analysis of structures from the point of view of speed, accuracy and robustness.
Bravenec, Ladislav ; Křiváková, Jarmila (referee) ; Němec, Ivan (advisor)
The aim of the thesis is to compare the iterative methods which program RFEM 5 uses the non-linear calculations of structures, namely the analysis of large deformations and post critical analysis. Comparison should serve as a basis for which calculation method is the most accurate, fastest and most reliable in terms of getting results. Time-consuming will be judged according to the calculation of the solution and the time needed to compute one iterativ. Robustness we will compare the reliability of methods in in normal use. Accuracy of the calculation will be determined by comparing the maximum deformation structures. Comparison will be made with examples from practice.
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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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Verification of nonlinear material models
Prokš, Tomáš ; Němec, Ivan (referee) ; Hradil, Petr (advisor)
The bachelor thesis deals with verification of nonlinear material model of soil FHWA SOIL during shear test. The nonlinear problem was being solved by software LS-DYNA using explicit formulation of finite elements method. The values of horizontal displacements during the direct shear test were compared with the results listed by the developer of the material. The considerable difference in the results led to focusing on the settings of the material model and influence of application of load, geometry and type of finite elements on the monitoring values.
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