ACTIVE VIBRATION CONTROL OF PLATE WITH INTEGRATED SENSORS AND ACTUATORS

Abstract

Active vibration control using piezoelectric sensors and actuators have recently emerged as a practical and promising technology. Efficient and accurate modeling of these structures bonded to or embedded with actuators and sensors is needed for efficient design of smart structures. This dissertation addresses the modeling of smart plate. A finite element model of piezolaminated composite plate based on first order shear deformation theory and linear piezoelectric theory is presented. Finite element has five mechanical degree of freedom per node and one electrical degree of freedom per piezoelectric layer. Finite element has n-host structure layer and two piezoelectric layers. In deriving the finite element model of piezolaminated plate first displacement equation is given followed by strain displacement relationship, constitutive equation of piezoelectric, force and bending moment relation, strain energy equation, electrical energy equation, work done by external forces and electrical charges, kinetic energy equation. Governing equations are derived using Hamilton's principle. Constant gain negative velocity feedback controller is used for vibration control. Genetic algorithm is used to obtain optimum voltage in oder to get desired shape of plate. A code is developed in MATLAB for making numerical studies. Code is validated for static and dynamic analysis with the available literature. Numerical studies is carried out in reference of layered composite plate for the effect of ply orientation angle on deflection, Effect of piezolayer thickness on the natural frequency, Variation of natural frequency with orientation angle of plate, Variation of Fundamental natural frequencies with patch coverage area, Effect of feedback control gain on transient response, Effect of sensor/actuator pairs position on the plate response, Mode shapes of plate, Shape control of composite plate and optimum voltage in order to get desired shape using genetic algorithm. Finally, it is observed that piezoelectric actuator can be used to control the shape of the plate. And a combination of sensor-actuator-controller can be used to suppress the vibration in composite plate.