ON THE DAMPING OF A PIEZOELECTRIC TRUSS

Abstract This paper re-examines the classical problem of active and passive damping of a piezoelectric truss. The active damping strategy is the so-called IFF (Integral Force Feedback) which has guaranteed stability; both voltage control and charge (current) control implementations are examined; they are compared to resistive shunting. It is shown that in all three cases, the closed-loop eigenvalues follow a root-locus; closed form analytical formulas are given for the poles and zeros and the maximum modal damping. It is shown that the performances are controlled by two parameters: the modal fraction of strain energy ºi in the active strut and the electromechanical coupling coefcient k. The paper also briey addresses the inductive shunting, for which a new parameter comes in: the tuning ratio!e=!i between the electrical circuit and the mechanical vibration. Due to space limitations, this paper includes only a small part of the sectional lecture at the 21stICTAM. 1