Application of Shunted Piezoelectric Materials in Aeroelasticity

Abstract

This paper presents a numerical study on the influence of multimodal shunt circuit parameters in the flutter velocity of a typical section under an unsteady airflow. Flutter on typical sections is a kind of self-excited oscillation which can occur due to the interaction with the airflow. In the flutter point, when the critical dynamic pressure is reached, the vibrations of the typical section become unstable and increase fast and significantly in time. As a result, it can lead the structure to failure. Thus, it becomes important to investigate the possibility of reducing the effects of flutter in order to increase the reliability of composite structures during service. In this work, the aero-electromechanical dynamic model formulation is based on the Hamilton principle. The unsteady aerodynamic forces are calculated based on the linearized thin-airfoil theory, proposed by Theodorsen. The passive element responsible for the energy dissipation is a multimodal resonant shunt circuit in series topology, attached to a piezoelectric patch. An iterative solution algorithm is proposed to solve the resultant nonlinear eigenvalue problem. The optimum shunt tuning is firstly performed using Hagood and Flotow’s propositions; then, it is used an heuristic optimization algorithm, based on Differential Evolution. The preliminary results indicate that the flutter speed can be affected by the passive control, both in its mechanical aspect as electrical.