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Finite element (FE) model of a square cantilevered plate instrumented with a piezoelectric sensor and an actuator is created using Hamilton's principle. Rotational degrees of freedom (dofs) of the FE model are eliminated using system equivalent reduction expansion process (SEREP). Experimental mode shapes and natural frequencies are extracted from the structure using high speed cameras and digital image correlation (DIC) technique. Initial FE model is updated using experimental mode shapes and natural frequencies by well-known Berman and Nagy approach. Updated FE model thus derived is further reduced to first three modes using orthonormal modal reduction technique. Modal model of the smart plate is then used to derive state space model of the smart plate. Two Kalman observers are constructed: one using initial FE model and other using updated FE model. Active vibration control experiments are conducted on the cantilevered using these two Kalman observers in the control law. It is observed that much better vibration suppression occurs when Kalman observer based on updated FE model is used in the control law. Strategy suggested in this work to implement a typical active vibration control scheme on a structure is simple and yet very effective. [ABSTRACT FROM AUTHOR]

Control of structural vibrations has significant applications in manufacturing, infrastructure engineering, aerospace engineering and various consumer products. In last two decades, considerable attention has been focused to suppress structural vibrations using active vibration control technique. Various researchers have proposed various optimization criteria for optimal placement of piezoelectric patches over a smart structure to suppress vibrations using various optimization techniques. This paper presents a review of various optimization criteria and techniques that have been used by various researchers in the field of smart structures. Mathematical expressions of objective functions of twelve optimization criteria have been presented and their justifications have been reasoned. Step by step procedures of commonly used optimization techniques have also been presented. [ABSTRACT FROM AUTHOR]

This paper presents a novel technique for Active Vibration Control (AVC) based on updated mathematical model of a mechanical structure. Vibrations of a smart plate instrumented with PZT sensor and actuator are suppressed using a negative velocity feedback controller. The AVC controllers are designed and compared for two cases. In first case it is assumed that there is a mismatch between the analytical model and the actual structure. In the second case the mismatch in analytical model and actual structure is compensated using direct method of model updating. Numerical simulations carried out in MATLAB software for these two cases demonstrate the improvement in performance of the AVC controller when updation is carried out. [ABSTRACT FROM AUTHOR]

In this work, a novel technique is proposed for generating desired transient vibrations in a structure. Cantilevered plate structure is instrumented with one piezoelectric sensor patch and one piezoelectric actuator patch. Quadrilateral plate finite element having three degrees of freedom at each node is employed to divide the plate into finite elements. Thereafter, Hamilton's principle is used to derive equations of motion of the smart plate. Finite-element model is reduced to first three modes using orthonormal modal truncation and subsequently, the reduced finite-element model is converted into a state-space model. Optimal tracking control is then applied to the state-space model of the smart plate. Using this optimal controller, cantilevered plate is made to vibrate as per desired decay curves of first three modes. Simulation results show that presented optimal control strategy is very effective in simultaneously tracking first three vibration modes of the smart plate. [ABSTRACT FROM AUTHOR]