ACTIVE VIBRATION CONTROL OF LAMINATED PLATE USING PIEZOELECTRIC SENSORS AND ACTUATORS

Based on the desirable properties of smart materials, many studies on the application of these materials in the eld of vibration control, damage detection, shape control and buckling control have been undertaken. For the design and analysis of smart beams, plates or shells, several considerations, such as the type and number of sensors and actuators and their locations, the method of modelling, and dierent analyses and the types of control system, are considered. In this paper, vibration control of a laminated composite plate, with piezoelectric actuators and sensors, is investigated. Governing equations of the laminated composite plate were derived using piezoelectric constitutive equations and Hamilton's principle. For modelling of the laminated plate, one of the numerical mesh-less methods; Element Free Galerkin (EFG), is used. In such methods, for discretization of a continuous eld, a scattered set of particles instead of elements are distributed in the eld, and the method of moving least squares (MLS) is used to construct the shape functions. In order to model the displacement and strain eld of the laminated plate, the rst-order shear deformation theory (FSDT) is used to consider its shear deformation eects. To verify the results, the natural frequency of isotropic and orthotropic plates with dierent boundary conditions was calculated and compared with other studies. The accuracy of the piezoelectric modelling is veried by calculating the displacement in dierent points of a bimorph piezoelectric beam in response to applying the electrical potential. After verication of the proposed method, the Newmark method is used to solve the dynamic equations of the laminated composite plate. For active vibration control of the laminated plate, a feedback control algorithm is used. The model is applied for the solution of two illustrative cases and the results are presented and discussed.