VIBRATION DAMPING USING PIEZOELECTRIC STIFFENER-ACTUATORS WITH APPLICATION TO ORTHOTROPIC PLATES

The converse piezoelectric effect is used to suppress the vibrations o f an othotropic plate stiffened with piezoelectric actuators. The cont rol problem involves the minimization of the dynamic response of the p late by using the voltage applied to the piezoelectric stiffeners as a control variable. The dynamic response is defined as a combination of the dynamic deflection and the velocity of the plate and expressed as a quadratic cost functional. The piezoelectric stiffeners are bonded on the opposite surfaces of the plate and placed symmetrically with re spect to the middle plane. The control forces and moments are activate d by applying in-phase or out-of-phase voltages, respectively. The act ive control takes the form of a piecewise constant alternating voltage with varying switch-over intervals to achieve optimum effect. Numeric al results are given to demonstrate the effectiveness of the proposed control mechanism and to investigate the effects of various problem pa rameters on the control of vibrations. Copyright (C) 1996 Elsevier Sci ence Ltd.