Optimal distribution of active piezoelectric elements for noise attenuation in sandwich panels

In this paper,a multiobjective optimization approach for obtaining the optimal distribution of surface-bonded piezoelectric sensors and actua-tors for noise attenuation in sandwich panels is presented.The noise attenuation is achieved by using negative velocity feedback control with co-located sensors and actuators.The control gains are also optimized in order to obtain the most efficient noise attenuation in a given frequency band.An in-house implementation of a viscoelastic soft core sandwich plate finite element,including surface-bonded piezoelectric sensors and actuators with active control capabilities,is used for obtaining the frequency response of the panels.The sound transmission capability of the panels is evaluated using the radiated sound power,along with the Rayleigh integral approach,which is suitable for lightly coupled structural/acoustic problems.The Direct MultiSearch(DMS)optimization algorithm is used to minimize the added weight due to the piezoelectric material,minimizing also the number of required controllers and maximizing the noise attenuation.The total length of the radiated sound power curve is shown to be an effective measure of noise attenuation in a given frequency band.Trade-off Pareto fronts and the obtained optimal configurations are presented and discussed.