INTEGRATION AND DESIGN OF PIEZOCERAMIC ELEMENTS IN INTELLIGENT STRUCTURES (REPRINTED FROM JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES, VOL 6, PG 733-743, 1995)

The design of induced strain elements (actuators) is a comprehensive i ssue, involving not only the materials and geometry of the elements, b ut also the behaviors of the coupled host structures. In particular, t he design of the active elements is essentially related to the predict ion of induced strain or stress in the elements. A high stress or stra in level in the actuators is useful to excite host structures; however , degradation or fatigue damage of the actuators may take place at the same time. This pager presents a dynamic analytical approach for the design and integration of active piezoceramic (PZT) patch elements loc ally coupled with host structures. Several critical design issues are addressed. These issues include the determination of the actuator dyna mic outputs, the prediction of energy conversion efficiency, the estim ation of system power requirement, and the limitation of induced alter nate peak stress. A coupled electro-mechanical analytical model was de veloped to reveal the inherent connections among these issues. Both th e mechanical stress behavior and the thermal stress characteristics of the PZT patch elements were investigated. A system power consumption- based model was developed to estimate the temperature and thermal stre ss distribution of the elements. The attention in parametric design wa s directed to the thickness and location of the elements. A simply-sup ported thin plate with surface-bonded PZT patches was built and tested to directly measure the induced dynamic strain of the PZT element so that the prediction accuracy and ability of the design model has been validated.