Panel flutter detection and control using eigenvector orientation and piezoelectric layers

A basic eigenvector orientation approach has been used to evaluate the possibility of controlling the onset of panel flutter using a simple flat panel (wide beam) as an illustrative example. The use of the eigenvector orientation method for prediction of the flutter boundary (indicated by a gradual loss of orthogonality between two eigenvectors) was developed in a previous study and can thus provide a lead time for possible flutter control. As a first step, piezoelectric layers are assumed to be bonded to the top and bottom surfaces of the panel in order to provide counterbending moments at joints between elements. The standard linear quadratic control theory is used for controller design and full state feedback is considered for simplicity. The controllers are designed to restabilize the system at the onset of flutter; as a result, flutter occurrence can be offset to a higher flutter speed. To illustrate the applicability and effectiveness of the developed method, several simple wide-beam examples are studied and presented. The effects of control moment locations are studied so as to fulfill the objective of adjusting the flutter speed to be within a desirable range. Potential applications of this basic method may be straightforwardly applied to plate and shell structures of laminated composites using the versatile finite element method. [PUBLICATION ABSTRACT]