Advanced Fatigue Damage Development in Graphite Epoxy Laminates.

Abstract

Results of an experimental investigation of damage development in T300/5208 graphite epoxy laminates subjected to tension-tension cyclic loading are reported. The concept of laminate stiffness reduction as a damage analogue is shown to be a valuable means of test control and damage interpretation. The relationship between stiffness and number of cycles is shown to be unique for each laminate type studied, each possessing three distinct stages, but markedly different among the laminate types. By using two complementary nondestructive evaluation (NDE) techniques, edge replication and penetrant-enhanced stereo X- ray radiography along with a method for deploying fatigue-damaged specimens, the stages of stiffness reduction were found to correspond variously to the predominance of matrix cracking or delamination or interactions of these matrix damage modes. A number of subordinate matrix damage modes including interior delamination, microcracking, and longitudinal splitting are identified with the matrix cracks which produce them. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1982
Accession Number
ADA130190

Entities

People

  • Kenneth L. Reifsnider
  • Russell D. Jamison

Organizations

  • Virginia Tech

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Space

DTIC Thesaurus Topics

  • Composite Materials
  • Delamination
  • Elastic Properties
  • Electron Microscopy
  • Epoxy Laminates
  • Graphitic Materials
  • Laminates
  • Material Degradation Processes
  • Materials
  • Materials Laboratories
  • Materials Processing
  • Materials Science
  • Materials Testing
  • Mechanical Working
  • Mechanics
  • Reinforced Plastics
  • Test And Evaluation

Readers

  • Structural Health Monitoring of Composite Structures.
  • Systems Analysis and Design