Accession Number : ADA293444

Title :   Materials for Adaptive Structural Acoustic Control. Volume 1.

Descriptive Note : Annual rept. 1 Feb 94-31 Jan 95,

Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK MATERIALS RESEARCH LAB

Personal Author(s) : Cross, L E.

PDF Url : ADA293444

Report Date : 06 APR 1995

Pagination or Media Count : 214

Abstract : The objectives of this ONR sponsored University Research Initiative (URI) entitled "Materials for Adaptive Structural Acoustic Control" concern both basic fundamental studies and highly applied development of the piezoelectric and electrostrictive ferroelectric ceramics which carry both the sensing and actuation functions for adaptive control. The report documents work over the third year of this five year program. For convenience and continuity, the activities are grouped under the headings General Summary Papers, Materials Studies, Composite Sensors, Actuator Studies, Integration Issues, Processing Studies, Thin Film Ferroelectrics, and the Abstracts of graduating students on the program. The first general papers illustrate the educational role undertaken by MRL faculty both in the basic understanding of ferroics, and in the philosophy of their application in 'smart' systems. It is interesting that through work pioneered on earlier ONR programs in MRL, it is now possible to measure both direct and converse electrostrictive response in simple solids, and to thus explore models to explain the signs and magnitudes of these striction constants. The relaxor ferroelectrics have been a topic of study for more than 30 years in the laboratory, but recent breakthroughs have revolutionized the level of understanding and opened a vista for further potential application of size (scale) effects in ferroics. Electrical control of shape memory has been achieved in a number of electro-ferroic solids, but full exploitation will need more complete understanding of both ferroelectric and ferroelastic: ferroelectric domain wall processes. (MM)

Descriptors :   *COMPOSITE MATERIALS, *CERAMIC MATERIALS, *PIEZOELECTRIC CRYSTALS, *ACOUSTIC ATTENUATION, *FERROELECTRIC CRYSTALS, VIBRATION, ADAPTIVE CONTROL SYSTEMS, DETECTORS, POLYMERS, ELASTIC PROPERTIES, THIN FILMS, ABSTRACTS, DIELECTRIC PROPERTIES, LEAD TITANATES, PIEZOELECTRIC MATERIALS, FATIGUE(MECHANICS), DOPING, ACTUATORS, HYDROPHONES, FERROELECTRIC MATERIALS, PHOTOVOLTAIC EFFECT, LANTHANUM, ELECTROSTRICTION, MICROCRACKING.

Subject Categories : Ceramics, Refractories and Glass
      Laminates and Composite Materials
      Acoustics
      Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE