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Měření, analýza a zlepšení hlukových vlastností železničních dvojkolí
Boháč, T. ; Šeděnka, M. ; Smutný, J. ; Pazdera, L. ; Pešek, Luděk
Within the long-term development of railway wheels with vibration and noise absorbers manufactured in the Bonatrans Group a.s., their numerical modelling is in process as well as their dynamic and vibro-acoustic testing in laboratories and in operation. This article provides a brief description of the methodology of operational measurements of the railway wheels noise with and without absorbers including the results obtained on the basis of the analyses of the measurements in the underground in Boston and Prague and on the test ring of the reference track in Cerhenice. The effectiveness of the applied absorbers resulting in reduction of the noise of moving vehicles on various tracks during various travelling modes is evident from the results.
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Measurement and analysis of tram wheel vibration at riding on track
Pešek, Luděk ; Vaněk, František ; Cibulka, Jan ; Vaněk, P. ; Boháč, T.
In the contribution the design, realization and results of vibro-acoustic measurements on the riding tram wheel is presented. The operational tests were performed on the tram KT8D5 of DPMB Brno. The tram wheel with a special rubber padding design was equiped with add-on vibro-acoustic dampers. Efficiency of the add-on dampers was evaluated from comparison tests on the tram wheel with and without these dampers. Third octave and time-frequency analysis of the measured vibro signals is herein presented for a bow track passage. For analysis of operational vibration modes the FE model of the wheel with add-on dampers was developed and applied.
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Evaluation of vibrational eigenfrequencies and eigenmodes and loss factor for monoblock rail wheel
Pešek, Luděk ; Veselý, Jan
The aim of this research was evaluated experimentally eigenfrequencies, eigenmodes and loss factors for the monoblock rail wheel in two options: a) without acoustic damping disc, b) with acoustic damping disk. Excitation was realized by an electrodynamic vibrator with different levels of excitation and by hammer. The raill wheel was forced on a wheel set placed on a special frame. Frequency range of modal analysis was up to 6400Hz with step 0.25Hz. The measurement and analysis was performed for all identifiable eigenfrequencies with emphasis on eigenmodes having from two up seven node radials without node cirles. Pro determination of eigenfrequencies and loss factors corresponding eigenmodes the modal analysis was carried out for all options of the damping disk.
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Design, development and realization of vibration measurement on riding metro wheel with and without add-on damper
Pešek, Luděk ; Vaněk, František ; Vaněk, Petr ; Cibulka, Jan
The aim of this research was design, developement and realization of vibration measurement (acceleration) of the riding metro wheel with and without add-on damper. The radiotelemetric method with four measurement channels was used for the operational measurement of vibration and noise. The solution was devided into four steps a) design and devolopement, laboratory tests and production of modified radiotelemtric equipment for measurement on the tram wheel; b) installation of the sensors and radiotelemetric equipment; c) realization of vibration operational measurement; d) measured data processing. In the report there is described a methodology of measurement and dynamic analysis used for comparision of the wheel with and withoud add-on dampers. The different riding regimes and tracks, i.e. direct, bow , were analysed. The third octave spectra nd amplitude time-frequency characteristics of accelerations and acoustic pressure were evaluated from the digital recorded time signals.
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Design, development and realization of vibration measurement on riding tram wheel with and without add-on damper
Pešek, Luděk ; Veselý, Jan ; Vaněk, František ; Cibulka, Jan ; Bula, Vítězslav
The aim of this research was design, developement and realization of vibration measurement (acceleration) of the riding wheel with and without add-on damper. The solution was devided into four steps a) design and devolopement, laboratory tests and production of modified radiotelemtric equipment for measurement on the tram wheel; b) installation of the sensors and radiotelemetric equipment; c) realization of vibration measurement of the carriage KT8D5; d) measured data processing. In the report there is described a methodology of measurement and dynamic analysis used for comparision of composed rim-rubber-disk wheel with and withoud add-on dampers. The different riding regimes and tracks, i.e. direct, bow and cross, were analysed.
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The noise impact on Prague market of dwelling: NSDI of road noise versus NSDI of tram noise
Šohajová, Renata ; Melichar, Jan (advisor) ; Máca, Vojtěch (referee)
This paper is studying an impact of price of noise on a market price of dwelling. I focus on a difference of impacts of road and tram traffic especially. I use a hedonic price model for Prague data. I illustrate a noise concept and its impact on people and society in theory because it encourages economics. I describe the hedonic price model and Noise Sensitivity Depreciation Index. I describe a descriptive analysis, regression analysis, modeling of hedonic price function of tram noise and road noise in practical part. I learn I can't compare hedonic models of tram noise and road noise because noise coefficients are not significant and they are bad oriented. Therefore I create the hedonic price model for night noise that was only one significant and negative.
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Solution of Traffic Noise in Perspective of Neoclassical and Liberal Economics
Zelenka, Václav ; Vojáček, Ondřej (advisor) ; Lipka, David (referee)
Basic concepts used in the bachelor theses are defined in the introductory part, in particular noise and indicators applied in noise assessment. A brief description of current state of noise situation in the Czech Republic takes up. It focuses on overstaying of noise limits and determination of territory affected by noise. The next part of the theses is devoted to potential solutions of noise issues in neoclassical and liberal economics. In terms of neoclassical economics, especially economic evaluation of noise and cost -- benefit analysis are dealt with. Within liberal economics, attention is paid to civil law suits and judicial verdicts in noise causes. The closing part of the theses compares both neoclassical and liberal approaches and submits advantages and disadvantages of their solution of noise issues.
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