Accession Number:

ADA279224

Title:

Materials for Adaptive Structural Acoustic Control. Volume 4

Descriptive Note:

Annual rept. 1 Feb 1993-31 Jan 1994

Corporate Author:

PENNSYLVANIA STATE UNIV UNIVERSITY PARK MATERIALS RESEARCH LAB

Personal Author(s):

Report Date:

1994-04-11

Pagination or Media Count:

102.0

Abstract:

The research goals of this ONR sponsored University Research Initiative entitled Materials for Adaptive Structural Acoustics Control relate directly to the sensing and actuating material which must be integrated to function in adaptive control of acoustic structures. This report documents work in the second year of the program and for convenience the activities are grouped under the headings General Summary Papers, Materials Studies, Composite Sensors, Actuator Studies, Integration Issues, Processing Studies, and Thin Film Ferroelectrics. The general papers cover a new comprehensive description of ferroelectric ceramics and their applications, analysis of high temperature piezoelectric sensors and the possible application of nonlinearity in enhancing the smartness of ceramics and composites. Scale effects on ferroics are of increasing interest and the manner in which nano-scale polar regions control the properties of relaxor ferroelectrics is again emphasized. For material studies the detailed examination of the evolution of diffuse, then relaxor behavior in lanthanum modified lead titanate has been completed. Interest in the soft PZTs, relaxor and phase switching materials continues, with a new thrust developing towards a more complete description of domain walls and morphotropic phase boundaries in perovskites. Materials issues in the wear out and fatigue effects in polarization switching systems have been subjected to detailed evaluation and the precautions necessary to fabricate long lasting materials which will stand 109 switches without any fatigue are delineated.

Subject Categories:

  • Ceramics, Refractories and Glass
  • Laminates and Composite Materials
  • Manufacturing and Industrial Engineering and Control of Production Systems
  • Acoustic Detection and Detectors
  • Acoustics
  • Electricity and Magnetism

Distribution Statement:

APPROVED FOR PUBLIC RELEASE