Accession Number : ADA302154

Title :   Research on Advanced NDE Methods for Aerospace Structures.

Descriptive Note : Final rept. 1 Sep 89-31 Aug 94,

Corporate Author : DAYTON UNIV OH RESEARCH INST

Personal Author(s) : Frock, Brian ; Karpur, Prasanna ; Martin, Richard ; Matikas, Theodore ; Ruddell, Mark

PDF Url : ADA302154

Report Date : NOV 1994

Pagination or Media Count : 144

Abstract : Studies were conducted which determined the capabilities and limitations of ultrasonic NDE techniques for evaluating the interphase/interface region between the fiber and the matrix in metal matrix composites. The major developments include: a physical model of the elastic interphase region between the fiber and matrix in the fiber-reinforced materials; an ultrasonic wave propagation model; an experimental procedure for interface elastic property measurements experimental determination of the semi-empirical relationship between the ultrasonic shear wave reflection coefficient and the magnitude of the radial residual stress at the fiber matrix interface; a method for ultrasonic imaging of fiber fracture during single-fiber fragmentation testing of metal matrix composites; and a method for in situ ultrasonic imaging of fiber fragmentation during incremental loading tests. Applicability studies resulted in: the use of software gating techniques for imaging near entry surface anomalies in kevlar polyester radome materials; use of an entry surface echo removal algorithm to improve time of flight C-scan images of near entry surface delamination damage; modification of an entry surface echo removal algorithm for application to sparsely samples, depot collected ultrasonic B scan data; and development and use of two dimensional Fourier domain zero padding or producing high quality enlargements of small, sparsely sampled depot type C-scan data sets. Many of the applicability studies were conducted in cooperation with Air Force ALCs. (MM)

Descriptors :   *CERAMIC MATRIX COMPOSITES, *FIBER REINFORCED COMPOSITES, *METAL MATRIX COMPOSITES, *CERAMIC MATERIALS, *TITANIUM ALLOYS, ALGORITHMS, IMAGE PROCESSING, MICROSTRUCTURE, NONDESTRUCTIVE TESTING, FRAGMENTATION, STIFFNESS, ELASTIC PROPERTIES, OPTICAL IMAGES, FRACTURE(MECHANICS), SUPPLY DEPOTS, RESIDUAL STRESS, AEROSPACE CRAFT, RADOMES, ULTRASONIC TESTS, POLYESTER PLASTICS, MICROCRACKING.

Subject Categories : Ceramics, Refractories and Glass
      Laminates and Composite Materials
      Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE