OPTIMAL-DESIGN OF PIEZOACTUATORS FOR ACTIVE NOISE AND VIBRATION CONTROL

A generalized approach for the optimization of piezoactuator/substructure coupling for active noise and vibration control is studied. The effective bending moment induced by twin, rectangularly shaped piezoactuators surface-bonded to the upper and lower surfaces of a thin, flat plate is estimated from a static analysis of the composite structure. For the degenerate case of zero bonding layer (i.e., perfect bonding), the effective bending moment obtained from this study is compared with pre-existing methods. The optimal thickness of piezoactuators that maximize the effective moment under a constant electric field is estimated. This study shows that the optimal thickness of the piezoactuators approaches half the thickness of the plate (assuming a steel plate). The influence of Young's modulus of the piezoactuators, the bonding layer thickness, and the damping and material properties of the bonding layer on the optimal thickness of the piezoactuators is also presented. An increase in the Young's modulus of the piezoactuators reduces the optimal thickness of the actuators, and gives larger bending moments. The thickness of the bonding layer does not significantly affect the optimal thickness of the piezoactuators; however, thicker bonding layers give lower bending moments. Finally, the damping and material properties of commercially available bonding materials do not significantly influence either the optimal thickness of the piezoactuators or the induced bending moment, given the bonding layer is thin with respect to the composite thickness.