Ultrasonic Characterization of Highly Attenuative Thick Composites

Abstract

Thick composites manufactured from various fiber and matrix materials are being increasingly used for structural components. Conventional ultrasonic methods cannot be used to characterize nondestructively these highly attenuative materials. In this report we define the term 'THICK' from a nondestructive evaluation (NDE) point of view which pertains to poor signal-to-noise (S/N) ratio of the received propagated signal in contrast to 'THICK' as referred to the load-bearing limit. Ultrasonic nondestructive evaluation of such composites may involve analyzing the interaction of elastic waves with the physical properties of the material constituents. We developed ultrasonic transmission techniques which, when used in conjunction with specimens in the shape of wedges, steps or parallel plates, allow accurate measurement of attenuation and consequently evaluation of flaws in these materials. We will describe several ultrasonic methods developed for application to determine the variations in the attenuation to characterize thick composites.

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Document Details

Document Type
Technical Report
Publication Date
Jul 24, 1992
Accession Number
ADA253347

Entities

People

  • Narendra K. Batra

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Air Platforms
  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Acoustic Properties
  • Acoustic Waves
  • Composite Materials
  • Data Analysis
  • Elastic Waves
  • Fiber Reinforced Composites
  • Fiber Reinforced Polymers
  • Frequency Shift
  • Materials
  • Materials Science
  • Measurement
  • Military Research
  • Phase Velocity
  • Physical Properties
  • Standards
  • Test And Evaluation
  • Ultrasounds

Readers

  • Acoustical Oceanography.
  • Metallurgy
  • Reinforced Composite Materials