Shunted piezoelectric patches in elastic and aeroelastic vibrations

A procedure for a modal-based modeling and analysis of the effectiveness of shunted piezoelectric devices in increasing passive damping of elastic and aeroelastic systems is presented. Dynamical models with different levels of complexity, including both elastic and aeroelastic systems, have been considered in order to show the capability of the proposed approach. The numerical tests presented concern the description of several systems of aeronautical interest with piezoelectric devices to achieve a selective control of different modes. The linear aeroelastic modeling has been reduced to a rational polynomial transfer function, i.e., it has been represented in a linear state–space form which has allowed to extend the proposed piezo modeling to a general linear aeroelastic system. In particular, the aeroelastic application showed a weak capability of improving the stability margin, but a significant performance in the reduction of the gust response level in proximity of the critical condition of the system (e.g., when the flight speed is close to the flutter speed). Thus, a suitable performance of the piezo damper should be designed for any flight speed, altitude and Mach number. An optimal strategy to evaluate the electrical load for the tuning of piezo devices, as function of the flight speed (semi-active control), has been also proposed.