Ultrasonic Non-Destructive Testing of Materials.

Abstract

This report describes broadband measurements of ultrasonic dispersion and attenuation in cross-plied specimens of graphite-epoxy. Quantitative comparisons of dispersion and attenuation data are made by means of least-square fit algorithms implemented into the ultrasonic signal processing system. Reproducible measurements in graphite-epoxy have been obtained. Two new frequency-dependent attenuation measurement techniques are described for measurements in composite materials. One is a continuous-wave resonance technique and the other is based on the Kramers-Kronig relation to find the attenuation from measurement of the dispersion. The new techniques are expected to be especially useful for measurements in highly absorbent composite specimens. A firm basis for the technique has been established and measurements with graphite-epoxy specimens are described. Good agreement can be obtained between the various attenuation measurement techniques. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1980
Accession Number
ADA093812

Entities

People

  • Wolfgang Sachse
  • Yih-hsing Pao

Organizations

  • Cornell University

Tags

Communities of Interest

  • Advanced Electronics
  • C4I
  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Applied Mechanics
  • Broadband
  • Composite Materials
  • Continuous Waves
  • Dispersion Relations
  • Frequency
  • Graphitic Materials
  • Group Velocity
  • Materials
  • Measurement
  • Mechanics
  • New York
  • Phase Velocity
  • Resonance
  • Resonant Frequency
  • Signal Processing
  • Ultrasounds

Readers

  • Regression Analysis.
  • Spectroscopy.
  • Structural Health Monitoring of Composite Structures.