On the use of negative capacitances for vibration damping of piezoactuated structures

Vibrations of structures equipped with a piezoelectric actuator can be damped by connecting the electrodes of the actuator to a suitable electric circuit. The insertion of a negative capacitance in the electric circuit, able to compensate the reactive impedance of the piezoelectric actuator, rise up the damping performance of the device. In this paper different circuits containing a negative capacitance are proposed and optimized for both single-mode and multi-mode damping. A theoretical analysis is performed in the former case, yielding closed-form expressions for the achieved exponential time-decay rate of vibrations, whereas a numerical optimization is employed in the latter case. The proposed circuits show good performances in simulation for both single-mode and multi-mode damping.