Modal control of smart shells by optimized discretely distributed piezoelectric transducers

Active vibration control of the shell structures with discretely distribute d piezoelectric sensor and actuator patches is investigated. The quasi-moda l sensor is developed to estimate the dominant mode coordinates of the shel l from the outputs of the sensor patches, and a criterion for finding the o ptimal locations and sizes of the sensor elements is given by minimizing th e observation spillover. The quasi-modal actuator is also designed to actua te the designated modes by means of modulating the voltage distribution of the piezoelectric actuator patches, and a criterion for optimal placement o f the actuator patches is presented based on the energy and control spillov er consideration. Furthermore, the compensators are employed to filter out the residual components with high frequencies from the estimated modal coor dinates. Based on the quasi-modal sensor and quasi-modal actuator, the inde pendent modal control is performed approximately to control the vibration o f smart shells. The simulation examples show that the vibration of the shel ls can be controlled effectively by using the presented method. (C) 2001 El sevier Science Ltd. All rights reserved.