Research on Advanced NDE Methods for Aerospace Structures.
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)
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1994
- Accession Number
- ADA302154
Entities
People
- Brian Frock
- Mark Ruddell
- Prasanna Karpur
- Richard K. Martin
- Theodore Matikas
Organizations
- University of Dayton