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Experimental and Theoretical Analysis of Backscattering Mechanisms in Fiber-Reinforced Composites

  • R. A. Roberts
  • J. Qu
  • J. D. Achenbach

Abstract

For the purpose of ultrasonic backscatter measurements, a material can be considered homogeneous if the signals received from scattering by microstructure are below the detection sensitivity of the ultrasonic instrumentation. This condition exists when 1) microstructural inhomogeneities in density and/or elastic properties are sufficiently small (weak scattering), or 2) all the characteristic dimensions of the internal structure are sufficiently small (long wavelength scattering). The ultrasonic inspection of homogeneous materials for abnormalities is generally straightforward; if scattering is detected, it may be assumed that a flaw is present. The inspection of structurally inhomogeneous materials such as fiber reinforced composites, however, is complicated by the need to discriminate between scattering from nondefective microstructure, and from defects such as cracks, porosity, inclusion, etc. Thus the development of ultrasonic NDE techniques for fiber reinforced composites requires first a careful examination of the scattering characteristics of the defect-free composite microstructure, followed by an examination of the changes in the defect-free scattering characteristics caused by the introduction of defects.

Keywords

Crack Opening Displacement Composite Specimen Fiber Distribution Backscatter Signal Ultrasonic Inspection 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Springer Science+Business Media New York 1988

Authors and Affiliations

  • R. A. Roberts
    • 1
  • J. Qu
    • 2
  • J. D. Achenbach
    • 2
  1. 1.Material and Components Technology DivisionArgonne National LaboratoryArgonneUSA
  2. 2.The Technological InstituteNorthwestern UniversityEvanstonUSA

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