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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
61

Tuhost ramene průmyslového robotu / Stiffness of Industrial Robot Arm

Vogel, Jan January 2017 (has links)
Stiffness analysis of an arm of an industrial robot with linear kinematics during a drilling operation. For solving this problem are used optical scanners. Finding the optimal cutting force for drilling by criterions: minimal deformation of robots arms and, at the same time, the emerging vibration from the cutting process is also minimal.
62

Určení NVH parametrů rovinné desky / NVH parameter determinantion of plate

Bouchner, Michal January 2018 (has links)
The aim of this thesis is examination and verification of numeric model for solving acoustics and vibration problems. Specifically, we are speaking about cast iron plate machined from gearbox. Main objectives of this work is set of experimental and numerical analysis at this simplified part with follow-up numerical model, where same analyses examining not only structure, but especially acoustic space around were performed. Due to this we were able to compare data between experimental and numerical analyses and to be able to prove or disprove functionality and limitation of numerical model.
63

Výpočtová simulace vibrací gumového silentbloku / Computational simulation of vibrations of rubber damper

Krupa, Lukáš January 2018 (has links)
This thesis deals with computational modelling of rubber damper using Finite element method (FEM). This thesis includes experimental measurement of material properties of rubber subjected to static and dynamic loading and their implementation into viscoelastic and hyperelastic material models with respect to given task. Dependance of dynamic stiffness on loading frequency obtained from the simulation is validated with experimental measurement. In the end the difference between results is investigated and possible causes of that are introduced.
64

Analýza dynamických účinků v oblasti srdcovky železniční výhybky / The analysis of dynamic effects in the frog region of railway turnout

Balash, Arsen Unknown Date (has links)
This thesis is focused on measurement and analysis of dynamic effects on railway turnouts. Two same-type turnouts with different fastening elasticity were chosen. My attention was focused mainly on the crossing part of the turnout, where the highest dynamic impacts occur. The point of the thesis is comparison of the crossing part of turnouts in term of dynamic behaviour and assessment of influence of soft rail pads on spread of dynamic energy through the construction. A part of the thesis is choice of methodology of the measurement and proposal of convenient mathematical apparatus for analysing of the dynamic effects on crossings.
65

Návrh opatření pro snížení hluku Rootsova dmychadla / Proposal of Measures to Reduce Noise of Roots Blower

Fučík, Ondřej January 2021 (has links)
The Master‘s thesis deals with issues of noise and vibrations of Roots blowers. In the theoretical part, potential sources of noise and vibrations are described. Detailed knowledge of basic types of mufflers is summarized, and their suitability for the corresponding application is evaluated. The practical part is focused on performing experimental measurements of the Roots blower’s noise and vibrations and the main sources of noise are determined. Subsequently, the existing anti-noise measures are analyzed and the proposal for adjusting the current measures for further noise reduction is presented.
66

Laserový vibrometr s 2D rozmítáním / Laser vibrometer with 2D scanning system

Rajm, Martin January 2012 (has links)
This thesis deals in the theoretical part with the non-contact vibration measurement by single point Laser Doppler vibrometer and it concretes constructions used in practice. It deals also with the possibilities of the laser beam scanning to measure the vibrations in the plane and there are also listed suitable-commercial systems for this solution. Mentioned sweep is immediately necessary for 2D scanning vibrometer construction. In the practical part, the single-point laser vibrometer OFV-5000 was expanded by scanning galvo system, supplemented by a measuring cards for signal acquisition from the vibrometer and suitable control hardware was chosen for mentioned laser. For the resulting hardware assembly was designed and implemented in LabVIEW measurement software, to control the 2D scanning system, to set the position of the laser beam and to process and to visualize of measured vibration signals in the plane. The functionality of the developed measuring system was checked by performed measurement and visualization of the velocity vibration of restraint girder, excited by shaker.
67

Vibrodiagnostický systém / Vibrodiagnostic system

Bortlík, Pavel January 2015 (has links)
Thesis discusses bearings failure detection that is manifesting with increased levels of vibration and acoustic emission. The first part of my work gives introduction to common disorders arising on bearings during operation and negative effects on the bearing condition. Further the thesis makes the reader familiar with the terms of vibration and acoustic emission. The work includes a description of available methods for signal evaluation of vibration and acoustic emissions in order to diagnose the state of the bearings in the domains of time and frequency. In the practical part is explained the vibrodiagnostic concept with focus on bearing endurance test. Part of this practical test is a balance sheet for hardware with marginal parametres and a software description. The work is complemented with sorted database of processed topics from the magazine Orbit Bentley Nevada.
68

Analýza akusticko-vibračních parametrů kolejového roštu / The analysis of acoustic and dynamic parameters of the track skeleton

Ratislavová, Eva January 2013 (has links)
This diploma thesis is focused on experimental measurement and acoustic and dynamic behavior analysis of railway construction with the Y – steel sleepers and their comparison with concrete sleepers. The measurements were taken in situ, in suitable sections of a railway line. These sections meet the requirements of regional railway tracks in the Czech Republic. Monitored parameters were obtained by measuring a response of testing trains and were analyzed using frequency and time analysis. Based on these evaluations, comparisons of particular constructions and their recommendations for practice were made.
69

Analýza akustických a vibračních parametrů od železniční dopravy / Analysis of acoustic and vibration parameters from rail transport

Turčíková, Hana January 2014 (has links)
This diploma thesis is focused on operational testing of selected railway lines with different structures of superstructure. For the measurement purposes suitable measuring sections in directional curves on the rail corridors were chosen and suitable measuring methodology was designed. Based on all the tests the dynamic and acoustic parameters of tested structures were determined. For the test evaluations suitable mathematic methods in both time and frequency zone was chosen. Part of my work is also to compare the parameters of the tested structures and to make recommendations for practise.
70

Analýza dynamických účinků působících na výhybky se zaměřením na stav konstrukce / The analysis of dynamic effects acting on the turnout with a focus on structural condition

Hajniš, Jan January 2014 (has links)
Author´s name: Bc. Jan Hajniš School: Technical University - VUT, Brno Faculty of Civil Engineering Veveří 331/95, 602 00 Brno Program: Construction and Transportation Engineering Title: The Analysis of dynamic effects acting on the turnout with a focus on structural condition Consultant: Prof. Ing. Jaroslav Smutný, Ph.D. Number of pages: about 100 + attachments Number of attachments: about 340 Year: 2014 This work describes the size and the process of dynamic effect – vibrations and shift – cockles in crossing panel and switch panels of the turnout constructions on steel and concrete sleepers in time and frequency domain. It compares the results of the measurement between these turnout constructions. Dynamic effects are undesirable physical phenomena for operation each train. It is therefore necessary to eliminate these phenomena as much as possible. The result of this test will by means of software programm and measuring set help to determine precisely the advantages and disadvantages of using both turnout constructions, or even to propose their improvements or dimensions.

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