Damping of Hydroelastic Vibrations of the Plate Using Shunted Piezoelectric Element. Part II: Experiment

In this work, we explore the possibilities of passive damping the resonance vibrations of a cantilevered duralumin plate located on the free surface of a quiescent fluid. The harmonic excitation with a specified frequency is provided by the electromagnetic field, which is generated under a combined action of a light neodymium magnet attached to the structure and a superposed coil. Passage of the alternating current produced by the generator through the coil generates an electromagnetic force, which oscillates the plate. The oscillations are damped by a piezoelectric element connected to an external passive electric RL-circuit. Measurements of the plate vibrations are taken using a Polytec PDV-100 digital laser vibrometer with a sampling frequency of 48 kHz. The amplitude-frequency characteristics of the plate were obtained from the experimental studies. The values of inductance and resistance parameters of the external RL-circuit were selected in such a way as to ensure the most effective damping of the harmonic vibrations of the plate. It was shown that the peak value of the vibration velocity can be reduced by 20 times in air environment and by 2.5 times in the case of interaction with fluid.