Ultrasonic Attenuation as an Indicator of Fatigue Life of Graphite/Epoxy Fiber Composite.

Abstract

Microscopic imperfections in graphite fiber epoxy composites may be introduced during both fabrication and service. The tendency of graphite fiber composites to fall in a quasi-brittle mode (as defined by the absence of a substantial nonlinear region in the stress-strain curve) makes these composites more sensitive than many metals to microscopic imperfections. In fatigue, failure has been described as being "like sudden death; that is, the fatigue failure occurs without any visible evidence of damage". Thus, any means of nondestructively monitoring fatigue damage or predicting fatigue behavior of graphite fiber composites is likely to enhance their effective use. The purpose of this report is to present the results of an experimental study to investigate the ultrasonic attenuation and velocity as a function of the fatigue state of a graphite fiber composite subjected to transfer compression-compression loading.

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1979
Accession Number
ADA301730

Entities

People

  • Beth Doll
  • James H. Williams Jr.

Organizations

  • Massachusetts Institute of Technology

Tags

DTIC Thesaurus Topics

  • Aging (Materials)
  • Composite Materials
  • Death
  • Epoxy Composites
  • Fabrication
  • Fatigue Life
  • Frequency
  • Graphite Epoxy Composites
  • Graphitic Materials
  • Group Velocity
  • Laminates
  • Material Degradation Processes
  • Materials
  • Materials Processing
  • Materials Testing
  • Stresses
  • Tensile Strength

Fields of Study

  • Materials science

Readers

  • Reinforced Composite Materials
  • Structural Health Monitoring of Composite Structures.