Signal Processing Effects for Ultrasonic Guided Wave Scanning of Composites

Journal Article · Sat Apr 09 00:00:00 EDT 2005 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.1916793· OSTI ID:20655323

Roth, D J ^[1]; Cosgriff, L M; Martin, R E ^[2]; Burns, E A ^[3]; Teemer, L ^[4]

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1. NASA Glenn Research Center, Cleveland, OH 44135 (United States)
2. Cleveland State University, Cleveland, OH 44120 (United States)
3. Michigan Technological University, Houghton, MI 49931 (United States)
4. Florida A and M University - Florida State University, Tallahassee, FL 32310 (United States)

The goal of this ongoing work is to optimize experimental variables for a guided wave scanning method to obtain the most revealing and accurate images of defect conditions in composite materials. This study focuses on signal processing effects involved in forming guided wave scan images. Signal processing is involved at two basic levels for deriving ultrasonic guided wave scan images. At the primary level, NASA GRC has developed algorithms to extract over 30 parameters from the multimode signal and its power spectral density. At the secondary level, there are many variables for which values must be chosen that affect actual computation of these parameters. In this study, a ceramic matrix composite sample having a delamination is characterized using the ultrasonic guided wave scan method. Energy balance and decay rate parameters of the guided wave at each scan location are calculated to form images. These images are compared with ultrasonic c-scan and thermography images. The effect of the time portion of the waveform processed on image quality is assessed by comparing with images formed using the total waveform acquired.

• OSTI ID: 20655323
• Journal Information: AIP Conference Proceedings, Vol. 760, Issue 1; Conference: Conference on review of progress in quantitative nondestructive evaluation, Golden, CO (United States), 25-30 Jul 2004; Other Information: DOI: 10.1063/1.1916793; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
ALGORITHMS
CERAMICS
COMPOSITE MATERIALS
ENERGY BALANCE
IMAGE PROCESSING
IMAGES
NASA
SIGNALS
SPECTRAL DENSITY
THERMOGRAPHY
ULTRASONIC TESTING
WAVE FORMS