The Use of Piezo-ceramics as Distributed Actuators in Flexible Space Structures

Distributed segmented piezo-electric actuators bonded to an elastic substructure and embedded inside a laminated composite material are modeled. Static mechanical models for various actuator geometries exciting both extension and flexure in the substructural material are developed. The flexural static models for both surface bonded and embedded cases are then integrated into a simple dynamic model for a cantilevered Bernoulli-Euler beam. This integration leads to the ability to predict, a priori, the response of the structural member to an excitation voltage applied to the piezo-electric. These models are experimentally verified for the first several modes of an aluminum cantilevered beam with eight piezo-ceramics bonded on the surface near the root and for a cantilevered glass/epoxy beam with four embedded piezo-ceramics. A scaling analysis demonstrates that the effectiveness of piezo-electrics scales with the structure, and allows the evaluation of candidate piezo-electric materials. Thesis Supervisor: Dr. Edward F. Crawley Title: Associate Professor of Aeronautics and Astronautics