Piezoelectric Stiffener-actuators For The Suppression Of The Vibration Of Laminated Composite Beams

The converse piezoelectric effect is used to suppress the vibrations of a laminated composite beam stiffened with piezoelectric actuators. The control problem involves the minimization of the dynamic response of the beam 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 beam and expressed as a quadratic cost functional. The piezoelectric stiffeners are bonded on the opposite surfaces of the beam and placed symmetrically with respect to the middle plane. The control moments are activated by applying out-of phase voltages. It is found that the optimal active control takes the form of a piecewise constant alternating voltage with varying switch—over intervals.