<title>Broadband piezoelectric shunts for passive structural vibration control</title>

Abstract

This paper reports an advanced passive piezoelectric shunt damping technique called broadband piezoelectric shunting. The shunt circuit for the broadband shunting is built with a reactance neutralizing circuit, which is designed with operational amplifier circuits to maximize the parallel reactance of the shunt circuit over a wide frequency band. It is different from the earlier shunt circuits, either used for the single- or multiple-mode shunting, which were built with inductors or simulated inductor circuits. In these earlier shunt circuits the anti-resonant frequency of the shunt circuit, with the inclusion of the piezoelectric transducer, was tuned with the inductor to a specific frequency to match with the natural frequency of the mode to be controlled. We first describe how the concept of the broadband shunt circuit was conceived and developed. We next report the shunt damping experiments performed on three difference structures: a thin aluminum cantilever beam, a two-wing aluminum cantilever beam, and a small-scale thermoplastic composite fairing. We have successfully demonstrated broadband amplitude reduction of structural vibration modes over a wide frequency band using the broadband shunt-damping technique. More detailed experimental results will be presented.