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Shape optimization of shield of asynchronous machine
Dítě, Pavel ; Hadaš, Zdeněk (referee) ; Dušek, Daniel (advisor)
The subject of this diploma thesis is to optimize the shield of asynchronous motor. In the thesis are given results of modal and the strain-stress analysis made for model of the shield, which is currently produced. To resolve this issue was used CAE programming system Pro/MECHANICA, which is based on method of geometric elements – GEM. The main output of this work is proposal of two new optimized shields of asynchronous motor and for these are presented results of modal analyse and the strain-stress analysis. Part of the thesis is design and technical-economic evaluation of casting methods for new shield production.
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Modelling of dynamics systems with multi degrees of freedom
Světnický, Tomáš ; Lošák, Petr (referee) ; Dušek, Daniel (advisor)
The goal of this thesis is to create a mathematical model of multi-degree-of-freedom vibrating system based on motion equations. The introduction describes the theoretical distribution of dynamic vibrating systems and their main characteristics. The next part deals with the analysis of assigned system and the motion equations are constructed by using Lagrange equations of the second kind. The process of system solving is provided together with equations which were used for obtaining the natural frequencies, eigenmodes and amplitudes of objects in time. The actual solution is carried out in MAPLE software; graphs of amplitude characteristics, phase characteristics and objects amplitude in time are constructed. Influence of parameters entering the calculation is discussed. At the end is verified the accuracy of the analytical solution by the finite element method in ANSYS software.
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Comparision of methods for nonlinear dynamic sytems solution
Krejčí, Jaroslav ; Lošák, Petr (referee) ; Dušek, Daniel (advisor)
The aim of this work is to make a solution of nonlinear dynamic system with one degree of freedom using various approximate analytical methods and perform their comparison. The beginning of the work describes the basic characteristics of nonlinear dynamic systems, methods of modelling and a description of the basic analytical methods of solution. In the following part is the solution of the system using described methods and comparing of results. In conclusion the methods are compared with final element method by program ANSYS.
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Modelling of dynamics systems with multi degrees of freedom
Ondra, Václav ; Donát, Martin (referee) ; Dušek, Daniel (advisor)
The aim of this work is for a dynamic system with multiple degrees of freedom to assemble and solve the equations of motion. In the beginning of work are summarized the basic knowledge about the dynamic oscillating systems, their distribution, method of mathematical description etc. In the following part of work are for the given set of particles assembled equations using Lagrange equations of the second kind. The solution of equation is made in mathematical system MAPLE for frequency domain. To determine the position of particles in time was used MATLAB. Research results are graphs of amplitude and frequency characteristics and graph of positions of particles in time. There is discussion on the influence of systems parameters on oscillation. The conclusion is a comparison of analytical solution with the solution of finale elements conclusion in ANSYS.
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Influence of eardrum perforation position and eardrum perforation size on ear sound transfer function
Straka, Martin ; Dušek, Daniel (referee) ; Pellant, Karel (advisor)
This thesis describes influence of eardrum perforation and perforation patching (myringoplastics) on sound transfer function. Perforation size, perforation position and inluence of graft material on hearing are discussed. This thesis is completed with 3D mathematical modeling in ANSYS system. The 3D finite element model of human ear is remodeled to represent the perforated and graft covered stage. Mathematical modeling is used for sound transfer calculations and for the discussions of the influence of tympanic membrane perforation on hearing. Set of audiological examination is processed and it is made the comparison between mathematical modeling results and audiology results.
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Aerodynamic noise of computers
Zouhar, Lukáš ; Dušek, Daniel (referee) ; Pellant, Karel (advisor)
This submitted thesis pursues a theme of decreasing the computer noise, especially focusing on the aerodynamic noise of the cooling fans, possibilities of decreasing the noise by fan optimization, using rubber bolsters and sound-isolating layers or construction changes in the very fans and their placing. We shall also aim on the relation between the created noise and the blade shape or rotation speed.
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Modelling of vibration of dynamic systems with n-degrees of freedom
Horák, Petr ; Hadaš, Zdeněk (referee) ; Dušek, Daniel (advisor)
The aim of this work is to assemble mathematical model for given system of point masses. Compute the natural frequencies and their corresponding modes of vibration. Differentiations of vibration by various points of view are written in this work. The given system is analyzed and the equations of motion using two most common methods are written. Calculation procedure of mentioned physical quantities is written in order from simplified to complete system of point masses. This procedure is used in command file to express values numerical. The frequency response of the system and the displacement-time plots are shown. The impact of constant variability entering the calculation is described.
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Modelling of vibration of dynamic systems with n-degrees of freedom
Luky, Robin ; Hadaš, Zdeněk (referee) ; Dušek, Daniel (advisor)
This Bachelor’s thesis deals with vibration of dynamic systems with luminous parameters with n-degrees of freedom. It features decision procedures of free-running undamped systems, exciting undamped systems, exciting damped systems and their natural shapes, natural frequency and gain-frequency characteristic. At the end of this Bachelor thesis there is an analysis of dynamic damper. The analysis is conducted in agreement with the theoretical procedures listed above.
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