Materials for Adaptive Structural Acoustic Control. Volume 3

This report documents work carried out in the Materials Research Laboratory of the Pennsylvania State University over the first year of a new ONR sponsored University Research Initiative URI entitled Materials for Adaptive Structural Acoustic Control. For this report the activities have been grouped under the following topic headings 1 General Summary Papers 2 Materials Studies 3 Composite Sensors 4 Actuator Studies 5 Integration Issues 6 Processing Studies 7 Thin Film Ferroelectrics. In material studies important advances have been made in the understanding of the evaluation of relaxor behavior in the PLZTs and of the order disorder behavior in lead scandium tantalatelead titanate solid solutions and of the Morphotropic Phase Boundary in this system. For both composite sensors and actuators we have continued to explore and exploit the remarkable versatility of the flextensional moonie type structure. Finite element FEA calculations have given a clear picture of the lower order resonant modes and permitted the evaluation of various end cap metals, cap geometries and load conditions. In actuator studies multilayer structures have been combined with flextensional moonie endcaps to yield high displacement 50 micrometers compact structures. Electrically controlled shape memory has been demonstrated in lead zirconate stannate titanate compositions, and used for controlling a simple latching relay