Microstructure Effects on Acoustic Emission Signal Characteristics,

Abstract

Specimens of three types of graphite-epoxy composites were fractured in bending in both the unaged and hydrothermally aged conditions. Acoustic emissions detected during the various stages in the fracture process were analyzed with a broadband system in the time and frequency domain and correlations were made between characteristics of the emissions and features of the load history, hydrothermal treatment, and topography of the fracture surfaces. Measurements were also made of the acoustic velocity, attenuation, and dispersion in a plate and in bars of one of the materials. Several attempts were also made to quantify observations made during the previous year's study of the sources of acoustic emission in commercial aluminum alloys.

Document Details

Document Type
Technical Report
Publication Date
Aug 01, 1976
Accession Number
ADP003013

Entities

People

  • L. J. Graham

Tags

DTIC Thesaurus Topics

  • Acoustic Emissions
  • Acoustic Velocity
  • Aluminum
  • Aluminum Alloys
  • Broadband
  • Composite Materials
  • Emission
  • Epoxy Composites
  • Frequency
  • Frequency Domain
  • Graphite Epoxy Composites
  • Graphitic Materials
  • Materials

Fields of Study

  • Materials science
  • Physics

Readers

  • Acoustical Oceanography.
  • Materials Science and Engineering.
  • Structural Health Monitoring of Composite Structures.