Self-Tuning Multimodal Piezoelectric Shunt Damping

Abstract

Piezoelectric shunt damping is a well known structural vibration control technique that consists in connecting an electrical circuit to a piezoelectric transducer attached to the structure. In the case of a resonant shunt, the network consisting of an inductor-resistor network when combined with the capacitive nature of the piezoelectric transducer impedance can be designed to act as a tuned vibration absorber. This paper discusses a method for the design and online adaptation of multimodal piezoelectric resonant shunts. The method presented in this work is different from previously multi-modal shunting methods (current blocking and current flowing) and implements the shunting network with a reduced number of discrete electrical components besides allowing for online tuning of the shunting parameters. The mathematical model of a structure with bonded piezoelectric transducers connected to a general electrical network is reviewed and the coupled equations of motion of a simply supported beam with piezoelectric elements and passive shunt networks are derived. The design of the multimodal shunt network is presented based on passive filter synthesis methods. The multimodal self tuning piezoelectric damper is demonstrated experimentally as a two-mode system applied to add damping to a cantilevered beam.