Laminated composite structures have been widely used for aerospace applications such as satellite, and aircraft components. Excessive vibration in these structures may result in instability and/or poor functionality of the system. In order to control the stability of the laminated structures during operation, conventional laminated composite structures have been combined with sensing and actuating capabilities of piezoelectric materials to develop "smart laminated structures". Efficiency and accuracy of the static and dynamic responses of the smart systems highly depend on the mathematical modeling of the structure and the control strategy. Thus, to achieve the desirable performance and functionality of the smart laminated systems, these two aspects should be accurately represented in the modeling. Mathematical modeling of smart laminated structures has been performed mainly by using Equivalent-Single Layer (ESL) theories [1]. However, due to the existence of different materials and geometries such as piezoelectric materials, graphite/epoxy and adhesive, smart laminated structures contain strong inhomogenities through the thickness. Thus, to account for the material and electro-mechanical inhomogenities in these hybrid laminates, it is required to develop a robust electro-mechanical model to provide accurate prediction of static and dynamic responses of the structure. It has been approved that the layerwise displacement theory can provide high efficiency (compared to 3D models) and accuracy (compared to ESL) for the analysis of laminated structures [2]. On the other hand, dynamic performance and functionality of smart laminated structures for vibration control strongly depends on appropriate control mechanism and strategy. Research works on vibration control of laminated composite structures are very limited and still there are many issues that remain unexplored. Previous works are mainly limited to a negative velocity feedback as the controller and application of ESL theories to model the structure [4]. It has been shown that for the isotropic materials, Linear Quadratic Regulator (LQR) [3] is the most efficient approach (compared to classical strategies) to determine the optimal feedback gain [4]. To the best knowledge of the authors, optimal control has not been utilized for laminated composite structures in general, and also the layerwise displacement theory has not been used for the mathematical modeling for vibration control.
展开▼
