An acousto-ultrasonic NDE technique for monitoring material anisotropy
A simpler and better way of monitoring the anisotropy of fiber-reinforced composite materials, based on the acousto-ultrasonic approach, is presented. In this approach, time of flight of the acousto-ultrasonic waves AU, rather than the stress wave factor, is measured. Two fundamental Lamb modes are generated under the first critical frequency: one is the first antisymmetric mode traveling with a slower velocity while the another is the first symmetric mode traveling with a faster speed. The later one is sensitive to the azimuthal angle and nearly nondispersive, and has a phase velocity very close to that of the bulk longitudinal wave of the material. Experimental data measured from two methods, TOF measurement and slope method, are compared with theoretical results; a good agreement is obtained for monitoring the material anisotropy. There is a great potential for this AU approach in material-property evaluation and in quantitative measurements of defects and debonding of fiber-reinforced composites. However, more studies are needed to better understand the effect of the fiber/matrix bonding on the measurements and to extract more information from the AU signals.
- Research Organization:
- Argonne National Lab., IL (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 10106259
- Report Number(s):
- ANL/CP--75819; CONF-9207155--2; ON: DE93002994
- Country of Publication:
- United States
- Language:
- English
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