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Design and production of pendulum tuned mass damper
Čupr, Michal ; Rubeš, Ondřej (referee) ; Kšica, Filip (advisor)
In a real environment, various external conditions can cause vibration of the machines, buildings or other systems. To prevent vibration of the system with low frequencies, pendulum tuned mass damper can be installed. The first part of this thesis describes the oscillation of simple structures for systems with one or two degrees of freedom. This analysis is then applied to mechanism that contains pendulum tuned mass damper. The damper’s principle is explained along with its important parameters and properties. Design and tuning of the damper are explained. Text continues with description of several types of the damper and there are mentioned some examples of their applications. In the final part, a model of the mechanism with pendulum tuned mass damper is designed and it is described mathematically using programs Matlab and Ansys. Subsequently, the model was made and the real model was compared with mathematical model. It was found that effectiveness of the damper depends most on the natural frequency of the system and the dissipation energy from it. The manufactured pendulum damper effectively dampens the oscillation of the real model, and the course of its oscillations corresponds to the mathematical model.
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Vibrodiagnostics of electrical machines
Petráček, Samuel ; Cipín, Radoslav (referee) ; Janda, Marcel (advisor)
This bachelor's thesis deals with getting to know vibrations and their description. What types of vibrations occur, what are their parameters, such as deflection or acceleration, and a slightly described frequency analysis for non-harmonic signals. Subsequently, the sources of vibrations in electric rotating machines are described. Types of vibration sources are described here, for example of mechanical origin or on the bearing. The causes of their occurrence are, for example, rotor imbalance, rotor misalignment or mechanical loosening. And their subsequent effect on the machine in axial and radial directions. Furthermore, the Crest Factor measurement method and a summary of other diagnostic methods of vibrodiagnostics such as Envelope Analysis and Kurtosis Factor are described. For what purposes these methods are used and their advantages and disadvantages. In the practical part, 4 asynchronous motors were measured with prerequisites for faults with rotor eccentricity. The effective values of the vibrations and the Crest Factor were calculated here, followed by a frequency analysis using FFT (Fast Fourier Transform). In the end, the resulting data were evaluated.
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Machining of long cylinders
Nádvorník, Vít ; Jaroš, Aleš (referee) ; Fiala, Zdeněk (advisor)
The bachelor thesis deals with the machining of long cylinders and production machines used for the machining technology. The main part contains a description of the vibration system of machine-tool-workpiece and analyzes active and passive methods of its elimination. It also deals with the wear of the cutting tool and a description of the parameters which have a direct effect on tool life.
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Use of Vibrodiagnostics in Forensic Engineering
Záleská, Veronika ; Bradáč, Albert (referee) ; Panáček, Vladimír (advisor)
This thesis deals with the measurement and evaluation of vibration on selected parts of car. Part of the work is devoted to the theory of vibration and noise, which includes, among others, presentations of common disorders of machine parts in terms of vibration. In the practical part of the work were performed out measurements described here and the results analyzed. Last part is in short devoted to the possibilities of using a similar measurement in forensic engineering.
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Dynamic analysis of structure loaded seismic loads
Janošková, Lenka ; Nevařil, Aleš (referee) ; Vlk, Zbyněk (advisor)
In this diploma thesis the seismic load on two different models is solved – the first model is a beam hall and the second model is a multistory building. The calculation of seismic load was performed according to standard ČSN EN 1998-1 (Eurocode 8) using the response spectrum analysis and the method of equivalent static forces (substi-tute load). For the combination of seismic responses in different directions are used SRSS and CQC rules. Models and calculations were solved in a student’s version of program RFEM 4.10 (Ing. Software Dlubal, s.r.o.). The comparison of mentioned methods in each models, also the comparison of combinative rules in calculation and the final evaluation of seismic responses on both of models are the subject of this thesis.
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Materials for Production of Chords for Musical Instruments
Krhut, Štěpán ; Němec, Karel (referee) ; Molliková, Eva (advisor)
My bachelor’s work is about materials used for making the musical strings and its protection against its wear off. The introduction deals with evolution and history of the musical strings and the next chapters explain physical basics of the vibrations and how to make the musical string. There are also highlighted and many times mentioned guitar strings in my work due to the string manufacturers are made to develop and implement various high level demands into the strings because of the many various guitar playing techniques.
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Design of Data Acquisition Equipment IMC Fastening System in the Car
Černý, Martin ; Jeník, Radomír (referee) ; Ramík, Pavel (advisor)
Devices for measuring the dynamic load and vibration of certain parts of the bodywork or parts of other parts of the vehicle are made using accelerometers and measuring instruments IMC. It must be simply installed into the interior of the vehicle so that it is not necessary to remove any parts of the interior and to avoid damage to all parts of the interior. The preparation must also withstand the considerable dynamic load generated by the harder operation tests.
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Methods for Kármán vortices suppression
Kukrle, Daniel ; Urban, Ondřej (referee) ; Rudolf, Pavel (advisor)
This bachelory thesis is considering a Kármán vorticies and their suppresion. The theoretical part describes principle of phenomenon origin and concepts connected with this topic. Following chapter deals with Kármán vortex street occurrence and danger. In the end of the first part there is an overview of phenomenon suppresion methods. Experiment applies selected suppresoin methods and proves their effectivness.
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