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Kinematic system for measurement of dynamic parametes of vibrationg parts under rotation
Pešek, Luděk ; Vaněk, František ; Procházka, Pavel ; Vaněk, Petr ; Cibulka, Jan ; Bula, Vítězslav
Kinematic system for measurement of dynamic parameters of vibrating parts under rotation.In the contribution the research on the improvement of the kinematic measuring system for evaluation of natural and forced vibration of machinery parts under rotation is presented. The improvement was aimed at the sensor part for a continuous movement of rotating and vibrating disk. For this reason the numerical FE model of the physical model of bladed disk was developed and analyzed. Laboratory verification of the new proposed sensor system was performed under an electromagnetic harmonic excitation. By means of strain-gauge measurement that were placed on several disk blades with a slip-ring signal transmission, the dynamics of the rotor was analyzed and the kinematic system was calibrated.
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The vibrodiagnostic system VDS-UT2 for the investigation of a tram wheel operational vibration and deformation
Pešek, Luděk ; Vaněk, František ; Balda, Miroslav ; Procházka, Pavel ; Vaněk, Petr ; Cibulka, Jan ; Bula, Vítězslav
The system consists of both measuring, acquisition and processing tools for monitoring of tram wheel and wheel set operational parameters,e.g.static and dynamic deformation, displacement, velocity, acceleration and temperature. The measuring on the rotating wheel is realized both by telemetric and by time difference system. Measured data can be remote observed via internet connection with the control PC. Tha acquisition system by Starmans s.r.o provides continuous analog and digital data collection. The control PC processes digital logical signals and evaluates time intervals representing circumferential turning angles between disk and rim. In the contribution the diagnostic system is described and the measured data with damage analysis are presented.
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Teplotní účinek na rheologické vlastnosti pryžového prvku
Půst, Ladislav ; Pešek, Luděk ; Vaněk, František ; Bula, Vítězslav
Deformation and temperature data of a vibro-damping element measured in laboratory condition at harmonic loading with constant prload F st =6kN were elaborated with the aim to build termo-mechanical characteristic of rubber-like material. It is shown that the increase of temperature during harmonic loading at various amplitudes F0=(0,75,3) kN and frequencies fe(10,30) Hz is exponential in time and proportional to the square of loading amplitude. The proposed mathematical model of dynamic characteristic of specimen gained by the regression procedure consists of linear, quadratic and fourth root function of displacement amplitude Xo and of the linear correction function of temperature.
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Physical Model of the Vocal Folds
Kryštůfek, Jan ; Bula, Vítězslav ; Horáček, Jaromír
Assuming symmetry of self-oscillations, a half physical model of the vocal folds was made. Working principle of the model is based on self-induced oscillations occurring when a critical air flow rate is crossed. Air flow rate of 0,6 l/s was used for generation of flow-induced oscillations of elastic part of the model with fundamental frequency 117 Hz. Used elastic element made of polyurethane rubber was designed and manufactured by Thomson from Purdue University (Indiana) [1], [2]. The introductory measurements were performed by using a high speed digital camera. We propose to use the model as a source of acoustic pressure for excitation of physical models of the human vocal tract.
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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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