Increasing the performance of negative capacitance shunts by enlarging the output voltage to the requirements of piezoelectric transducers

Abstract

Piezoelectric shunt damping is investigated as one possible solution for improving the vibroacoustic behavior of noise-prone lightweight structures. The negative capacitance shunt circuit appears to be best choice due to its broadband damping effect. Usually it is built from analog electronic components, such as operational amplifiers, resistors and capacitors. Laboratory tests are possible with this setup, but it is limited to low vibrational excitation levels, because the known circuits are not capable of accessing a sufficient voltage amplitude at the piezoelectric transducers, which is required for high vibration amplitudes. Therefore an improved approach is presented in this paper, which addresses the specific voltage requirements of a common piezoelectric transducer. It comprises a tailored power source and an appropriate concept for the negative capacitance shunt hardware. There only standard operational amplifiers together with an external high voltage power amplifier circuit are used to cover the whole operating range of a piezoelectric transducer. A demonstrator board is developed and experimentally investigated at a test structure. Finally, the results are compared to a conventional setup. It can be shown, that using the full voltage range of the piezoelectric transducer allows higher damping of structures without any saturation effects.