Research on Advanced NDE Methods for Aerospace Structures
Abstract
This Final Report describes investigations of the capabilities and limitations of several digital ultrasonic NDE techniques for imaging defects in advanced aerospace materials. The goal of these investigations was to determine the feasibility and practicality of transitioning these techniques from the laboratory to field use. Studies of new digital data collection techniques, signal processing, image enhancement and image restoration techniques revealed that their use can significantly improve the resolution of features in ultrasonic images. The use of narrow software gates to collect data from digitized rf A-scans improved the resolution in C-scan images of closely-spaced planes in advanced composite materials. That technique was used to simultaneously generate C-scan images of: (1) material defects throughout the entire thickness of several 32-ply thick, graphite-epoxy composite materials. The depth resolution of ultrasonic B-scan images was improved by generating the images from axially deconvolved A-scans and from axially power-spectrum- equalized A-scans rather than from the rf A-scans. Lateral resolution in C-scan images was significantly improved by collecting data for the images from Wiener- deconvolved A-scan and from power-spectrum-equalized A-scans rather than from the rf A-scans.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1989
- Accession Number
- ADA226858
Entities
People
- Brian G. Frock
- Mark J. Ruddell
- Prasanna Karpur
- Richard W. Martin
- Robert J. Andrews
Organizations
- University of Dayton