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Evaluation of risk of buckling in columns with inaccuracies in geometry and load
Fischer, Jiří ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
The aim of this thesis is to analyse applicability range of relations for a critical load at buckling for columns with deflection from ideal column – initially curved column or eccentric load. The solution of this thesis is analytical and it comes from solving the differential equation of the deflection curve. This equation has different general solutions for both assumptions. The result achieved in this thesis is general recommendation for maximal values of eccentricity of load according to cross section. Next result is recommendation of maximum curve according to cross section. The chosen cross sections are circular, square, rectangular and thin tubes.
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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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Evaluation of risk of buckling in columns with inaccuracies in geometry and load
Fischer, Jiří ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
The aim of this thesis is to analyse applicability range of relations for a critical load at buckling for columns with deflection from ideal column – initially curved column or eccentric load. The solution of this thesis is analytical and it comes from solving the differential equation of the deflection curve. This equation has different general solutions for both assumptions. The result achieved in this thesis is general recommendation for maximal values of eccentricity of load according to cross section. Next result is recommendation of maximum curve according to cross section. The chosen cross sections are circular, square, rectangular and thin tubes.
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Pneumatic cylinder
Málek, Miroslav ; Štefan, David (referee) ; Klas, Roman (advisor)
Bachelor thesis contains description and categorization of pneumatic actuators, main part is devoted to linear pneumatic motors, their design and description of individual parts of the motor with respect to its function. Part of this thesis is devoted to buckling stability of the piston rod and brief description of the parts in the pneumatic circuit. Next part of the thesis is deals with description of mathematical model of pneumatic cylinder, which results in simulation of variables describing the operation of the motor. Simulation has been done on double-acting and single-acting pneumatic cylinder with return spring. This mathematical model also includes a friction force model.
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Analysis of possibilities of solution of buckling of a screw-shaped beam
Pokorný, Jan ; Fuis, Vladimír (referee) ; Burša, Jiří (advisor)
Bachelor’s thesis deals with the effect of the pretwist of a column on the increase in buckling load and also focuses on a column with rectangular cross section. This problem is divided into two main parts. The first one is represented by the column with a large thread pitch, the second one by a small thread pitch. The results are obtained by a numerical approach using MATLAB software. The verification is carried out via finite element software. The outcome of this thesis is plotting the ratio of the critical loads of the twisted and prismatic columns against the ratio of the side lengths of the rectangular cross section. The results are shown for both types of considered columns.
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Stability analysis of swinging props turbines
Bukovský, Petr ; Navrátil, Petr (referee) ; Skalka, Petr (advisor)
Master thesis deals with a computing simulation of two props turbines lines. The thesis output is gaining maximum possible load, at which a commencement of deformation stability critical state for various geometrical imperfections has not arisen yet. The calculation has been done by FEM in two different ways: linear solution (using a calculation conversion into eigenbuckling) and nonlinear solution (using a FEM deformation option). Result analysis compares both methods outcomes. Safety factor for the props operation has been proposed taking into consideration known influences on operating state.
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Calculation of workpiece deflection when machining
Grebeň, Petr ; Zouhar, Jan (referee) ; Píška, Miroslav (advisor)
Selected chapters of the science branch "Elasticity and strength" applied to manufacturing of thin parts with various solution approaches. Applying theory of bars and a non-linear differential equation for the deflection line of the second order to a machined shaft. Numerical calculation in the ANSYS program. Evaluation and design of solution variants to machine thin shaft parts without supporting them.
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Evaluation of risk of buckling in bimaterial columns
Benešovský, Marek ; Návrat, Tomáš (referee) ; Burša, Jiří (advisor)
Bachelor’s thesis contains the principle of determining the critical load of buckling of column with nonconstant parameters. There is a solution for the column composed of one and two materials and solutions for the column with two different cross-sections. An essential part of this work is the numerical solution, which is used for solving nonlinear equations in implicit form. In this work, these equations occur when solving columns of two materials and two different cross-sections. For the numerical solution, it is necessary to set an initial approximation. Initial aproximation and numerical solution are solved by a program, which was created for this work. In the final part, are stated several graphs. The most important graph represents relation of the ratio of approximate critical load obtained by interpolation of Euler's relation and critical load gained numerically on the ratio of Young’s modules of both materials.
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Evaluation of buckling risk at beams made of two various materials
Zvěřina, Martin ; Dušek, Daniel (referee) ; Burša, Jiří (advisor)
Aim of this work is evaluation of buckling risk at beams made of two various materials and delimitation limits for critical power buckling beam from two various materials by the help of relations for prismatic beam. Further is here processed analyst determination critical force buckling for free beam from two various materials and also analyst determination critical force buckling for fixed beam from two various materials.
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