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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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Simulation of toroid coils in Ansoft Maxwell 3D
Daněk, Michal ; Pfeifer, Václav (referee) ; Hanák, Pavel (advisor)
The master thesis is focused on the simulation of the toroid coils in Ansoft Maxwell 3D software, which uses finite element method for electromagnetic field simulation. Firstly the process creation of the geometric model toroid coil with seventy-five threaded is presented. It is necessary to debug this model and prepare it for the mesh generation. Physical properties are assign to this model and it gives rise to the physical model. We will set boundaries, excitation current, core material, winding material and the parameters for the mesh generations. New material Kashke K4000 will be created in the materials library and subsequently we will define its BH curve on the basis of datasheet. Analysis is made in two modes. Direct currents (7,5A; 10A; 15A; 20A; 25A) and (non)linear materials are used in magnetostatic solution. Toroid coil is excited by current pulse in transient solution. In Ansoft Maxwell Circuit editor a source which generates current pulse will be created. This excitation will be assigned to the toroid coil as an extern source through a terminal. Core material is linear in the case of transient analysis, because Ansoft Maxwell 3D doesn´t allow to use nonlinear material in this solution. Settings are different in transient and in magnetostatic analysis. End time and time step are entered to solve this task in transient analysis. Time points are entered too. Flux density and electromagnetic field strength are calculated in these time points and later it will be possible to view the results. Calculated fields are shown as the pictures in this thesis. The procedure how to use a field calculator in the postprocessing is given as well. The achievements are summarized in the conclusion.
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Creating geometrical models of selected implants of hip joint
Kohoutek, Jan ; Vosynek, Petr (referee) ; Návrat, Tomáš (advisor)
According to the specification, the concept of the thesis is a research study, which is supposed to present global overview of the hip joint arthroplasty. It involves a short summary of basic methods used in biomechanical measurements of bone tissue and provides a comparison among isotropic homogeneous, isotropic inhomogeneous and orthotropic inhomogeneous material models and their impact on the results of the stress-strain analyses. In the thesis, there is also a short list of popular implants used in present times as well as a few examples of creating geometrical models of some prosthesis.
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Static analysis of bell stool using modern geodetic methods
Mojrová, Martina ; Vlk, Zbyněk (referee) ; Nevařil, Aleš (advisor)
The aim is to create a static model assessment of construction bell stools using new geodetic methods. This means data processing from laser scanner called. Point Cloud to the geometric model, which can be imported into a variety of drawing and modeling programs. Furthermore, use this geometrical model to create a static model, in program ANSYS FEM model and then calculate the internal forces. Finally, assessment of structures according to EN 1995-1 Design of timber structures.
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