Structural vibration suppression by concurrent piezoelectric sensor and actuator

An electromechanical model is developed to predict the natural frequencies of a structural system with a piezoelectric sensor and actuator, Analysis shows that a generalized stiffness is induced in the closed-circuit condition and it is a function of the structure dimensions, the location of the piezoelectric elements, and the piezoelectric constant, The sensor and actuator equation derived from the electromechanical model shows that a single piezoelectric element can be employed concurrently in sensing and actuation. Experimental verifications of structural vibration suppression are conducted on a beam structure with surface-bonded piezoelectric elements as well as on two composite laminated structures-[0/90](6S) and [45/-45](6S)-with embedded piezoelectric sensors and actuators. Compared with previous studies of vibration suppression by separate piezoelectric sensor(s) and actuator(s), the concurrent sensing and actuation technique offers the advantages of improved performance and reliability as each piezoelectric element can be employed as sensor and actuator simultaneously.