Full Content is available to subscribers

Subscribe/Learn More  >

In-Situ Monitoring of Damage in SiC/SiC Composites Using Acousto-Ultrasonics

[+] Author Affiliations
Andrew L. Gyekenyesi, Gregory N. Morscher

NASA Glenn Research Center, Cleveland, OH

Laura M. Cosgriff

Cleveland State University, Cleveland, OH

Paper No. GT2004-54233, pp. 445-451; 7 pages
  • ASME Turbo Expo 2004: Power for Land, Sea, and Air
  • Volume 2: Turbo Expo 2004
  • Vienna, Austria, June 14–17, 2004
  • Conference Sponsors: International Gas Turbine Institute
  • ISBN: 0-7918-4167-7 | eISBN: 0-7918-3739-4
  • Copyright © 2004 by ASME


Acousto-ultrasonics (AU) is a nondestructive evaluation (NDE) technique that utilizes two ultrasonic transducers to interrogate the condition of a test specimen. The sending transducer introduces an ultrasonic pulse at a point on the surface of the specimen while a receiving transducer detects the signal after it has passed through the material. The aim of the method is to correlate certain empirical parameters of the detected waveform to characteristics of the material between the two transducers. The waveform parameter of interest is the attenuation due to internal damping for which information is being garnered from the frequency domain. Here, the three parameters utilized to indirectly quantify the attenuation are the ultrasonic decay rate, the mean square value of the power spectrum, and the centroid of the power spectrum. The sensitivity for each of these AU parameters was assessed with respect to the damage state of two types of SiC/SiC ceramic matrix composites (CMC). The two composite systems both had Hi-NicalonTM fibers with a carbon interface but had different matrix compositions that led to considerable differences in damage accumulation. Load/unload/reload tensile tests were performed and in-situ AU measurements were made over the entire stress range. After analyzing the AU parameters, the overall sensitivity of the AU technique to material change or damage was quantified and shown to correlate well with the observed damage mechanisms for both material systems. In addition, the AU response was shown to be dependent on the stress state of the composites. This stress dependent behavior was observed while unloading the specimens from the maximum stress, thereby, maintaining a constant damage state.

Copyright © 2004 by ASME



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In