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Powertrain Mountings in a Car Body
Dúlovcová, Gabriela ; Vopařil, Jan (referee) ; Drápal, Lubomír (advisor)
The main aim of this thesis is to give reasons and describe different conceptions of engine mountings that eliminate vibrations of powertrain in a car body of personal vehicle. Another part is a comparison of particular conceptions from construction views and features. At the end of the thesis, there is assessment and designed possible future development.
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Analysis of Powertrain Acoustic Properties
Ambróz, Richard ; Novotný, Pavel (referee) ; Dundálek, Radim (referee) ; Píštěk, Václav (advisor)
Dizertačná práca rieši problematiku analýzy akustických vlastností pohonných jednotiek. V úvodnej časti je teoretický rozbor fyzikálnych princípov vibrácií a hluku a prehľad súčasného stavu riešenia problematiky v oblasti návrhu pohonných jednotiek. Vlastná časť práce popisuje konštrukčný návrh elektrodynamického budiča vibrácií, návrh hodnotenia výsledkov merania a taktiež spôsob spracovania výsledkov. Akustické vlastnosti sú hodnotené pomocou normálových rýchlostí kmitania povrchu. V závere práce sú prezentované ukážky využitia metódy v praktických príkladoch spojených s návrhom pohonnej jednotky. Celé riešenie predstavuje ucelený spôsob analýzy vhodný pre rýchle hodnotenie vplyvu konštrukčných úprav na akustické vlastnosti.
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Vibration system control through embedded system
Genčanský, David ; Stehlík, Jiří (referee) ; Szendiuch, Ivan (advisor)
The importance of vibration and vibration tests is increasingly relevant given th growing number of mobile electronic devices. This thesis descibes the design of control vibrating shaker table, which is an essential element for vibration testing. At the beginning is an initial look on the problematics of vibration, vibration test and influences of vibrations on electronic components, solder joints and other parts uses in microelectronics. Provides insight to the principles of vibration measurement and controlling system used in industry. The workplace is designed for testing and measuring of vibrations. The workplace designed and developed in the LabVIEW enviroment based on CompactRIO platform.
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Design of the Differential Test Rig for Testing in Anechoic Chamber
Ivanič, Michal ; Řehák, Kamil (referee) ; Prokop, Aleš (advisor)
The diploma thesis describes the design of a test stand for experimental determination of vibroacoustic parameters of a part of the powertrain system. Thesis contains a research part, describing the problems of the drive system, vibroacoustics, measuring devices and also the division and the description of test stands. At the same time, the reasons for choosing a closed loop test stand are explained. Thesis also includes the results of analytical calculations and numerical results of FEM methods performed using ANSYS software, as well as drawing documentation of individual parts.
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Determination of transmission error at helical gear
Czakó, Alexander ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This diploma thesis primarily deals with the transmission error issue which is one of the dominant sources of vibration in gear pairs and transmission systems. The vibrations subsequently generate noise which is often subjected to increasingly stricter demands across the industry, including the automotive one. It turns out that reducing the peak-to-peak value of the transmission error has a beneficial effect on the vibro-acoustic properties of gears and gear pairs. This thesis aims to determine the transmission error under static conditions, since a gear pair with a low static transmission error is a good assumption for a low transmission error even under dynamic effects. The resulting values of the transmission error can be influenced already during the design of the gear macro-geometry. It is also suitable to apply micro-geometric adjustments – modifications to the gear teeth. For this reason, the search part of the thesis is dedicated to theoretical knowledge, especially concerning the geometry of gears, modifications of teeth and the overall transmission error and its determination. The transmission error can be determined in several ways, including a technical experiment. However, due to time and financial reasons, this is not always possible, and therefore, the possibility of using numerical simulations is offered. In this thesis, the approach using stress-strain quasi-static contact analysis using the finite element method in Ansys Workbench software is used. The advantage is, among other things, a good comparability of results. The input to the FEM analysis is 3D CAD geometry – in this case, it is specifically a helical gear pair with parallel axes. The model/assembly of this gear pair is created in PTC Creo software fully parametrically, so it is possible to generate arbitrary gear pair configurations by changing the input parameters, which significantly saves time. At the end of this diploma thesis, the stress-strain analysis of various gear configurations is evaluated, with respect to the equivalent stress and contact pressure. Furthermore, the static transmission error – its graphs and peak-to-peak values – is determined from FEM analyses for different gear geometry, including tooth modifications, and for various loading torques. Last but not least, the effects of contact/overlap ratio and centre distance are evaluated.
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Determination of transmission error at bevel gear
Fraňová, Zuzana ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This master’s thesis deals with the determination of the transmission error in spiral bevel gears and its minimization using tooth profile modification in order to reduce vibrations and noise of transmission systems. Gears are the primary source of vibrations transmitted through the shaft and bearings to the gearbox housing and adjacent surfaces that emit noise into the surrounding space. In order to increase the level of comfort and due to the legislative requirements, increasing emphasis is being placed on reducing the noise and vibrations of machine components, including transmission systems. This leads to the need to identify noise sources and evaluate them in terms of expected acoustic performance. The quality of the gear meshing can be judged by transmission error that is closely related to the noise and vibrations. To evaluate the quality of gears based on transmission error, experimental measurements are used that are costly and require quality equipment. Therefore, it is efficient to determine the expected transmission error already at the design stage using numerical methods. In this work a parametric model of bevel gear geometry and a numerical model for the simulation of gear meshing using FEM software Ansys Mechanical are created in order to determine the transmission error. Based on the transmission error, various load cases and gear modifications designed for transmission error reduction are compared.
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Flat Plates Vibrations
Zajac, Roman ; Řehák, Kamil (referee) ; Prokop, Aleš (advisor)
The diploma thesis is focused on vibration of the planar plates. It includes the computational and experimental approaches used to determine the mode shapes and frequencies (eigenvalues) of planar plates. This paper compares the analytical, numerical and experimental results of the modal analysis specifically the free-standing rectangular planar plate. The work also encompasses forced oscillation with harmonious excitement as a continuation of the obtained results from modal analysis.
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Active Vibration Damping/Chatter Control of Machine Tool Spindle Units
Škúci, Michal ; Blecha, Petr (referee) ; Březina, Tomáš (advisor)
This bachelor’s thesis describes the issue about machining, causes of spindle chatter and different ways of chatter damping. It evaluates advantages and disadvantages of different ways of damping. There was made and described simple simulation model on which searching simulations was made for purpose of receiving picture of behaviour of model for different parameters. Model of active damping was made too.
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Measurement of vibration in machine tools
Helienek, Matúš ; Hadaš, Zdeněk (referee) ; Vetiška, Jan (advisor)
This thesis contains general introduction to vibrodiagnostics starting with definition and classification of vibrations. Furthermore the thesis describes the theory of data acquisition of vibration intensity. This section includes also types of sensors, which are used for vibration measuring. Practical part deals with measurement as well as evaluation of cutting process.
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Energy Harvesting for Industry 4.0 Applications
Gajdošík, Róbert ; Šimek, Václav (referee) ; Smrž, Pavel (advisor)
Cieľom tejto práce je demoštrácia možností využitia energy harvestingu v priemysle 4.0, so zameraním na prototyp samonapájacieho vibračného senzoru. Vrámci práce bol vykonaný výskum techník pre zhromažďovanie a spracovanie dát ako aj výskum ohľadom senzorového vybavenie budúceho prototypu. V ďalšom kroku bol vykonaný výskum a získaný prehľad ohľadom energy harvesterov, metód presunu a manipulácie vyťaženej elektrickej energie, a spôsobu jej uchovania. Ďalej bol vybraný vhodný mikroprocesor s vhodnou výbavou ohľadom vstupu a výstupu napájania, energie a konektivity. Nakoniec implementácie boli vyriešené rozhrania medzi jednotlivými komponentami prototypu. Po vyhodnotení ďalšieho postupu bolo rozhodnuté vyvinúť software pre plánované rozhrania medzi senzorom a procesorom, ako aj spracovávanie dát za použitia vzorkovania a rekonštrukcie analógového signálu za použitia analógovo-digitálneho meniča. Ďalej bola vyvinutá jednoduchá časť software pre detekciu anomálií v očakávaných frekvenčných pásmach daného objektu, a otestovaný jednoduchý kód pre využite subsystému BLE. Nakoniec tejto časti projektu boli preskúmané možnosti vylepšenia účinnosti využitia energie použitej pre napájanie mikroprocesora. V poslednom kroku práce boli otestované všetky komponenty navrhnutého prototypu. V prvej časti bola otestovaná funkcionalita komponentov bez integrácie s ostatnými časťami systému. Bola testovaná presnosť vibračného senzoru, funkcionalita harvesteru, a otestované jednotlivé subsystémy mikroprocesoru. V druhej časti testovania boli testované interakcie jednotlivých komponentov, napríklad rozhranie medzi mikroprocesorom a vibračným senzorom, a testovanie korektnosti softvérových metód pre vypočítanie frekvencie monitorovaného objektu. V poslednom kroku testovania boli otestované množstvá enegie vyťažené piezoelektrickým efektom a porovnané s experimentálne overeným odberom energie kompletného obvodu. Následne boli tieto informácie využité k aproximácií ceny prototypu a jeho realizovateľnosti v praktickom priemyselnom prostredí. Výsledkom práce je funčný prototyp obvodu samonapájacieho vibračného senzoru a teoretický návrh efektívnejšej verzie založenej na experimentálnych metódach prenosu energie medzi harvesterom a úložistom energie, ako aj aproximácia jednotkovej ceny obvodu a vyhodnotenia jeho použiteľnosti v modernom priemysle.
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