Analysis of Local Delaminations and Their Influence on Composite Laminate Behavior.

Abstract

An equation was derived for the strain energy release rate, G, assoicated with local delamination growth from a matrix ply crack. The critical G sub C edge delamination onset in + OR - 25/902s graphite epoxy laminates was measured and used in this equation to predict local delamination onset strains in + OR - 25/90Ns, n =4, 6, b laminates. A simple technique for predicting strain concentrations in the primary load bearing plies near local delaminations was developed. These strain concentrations were responsible for reduced laminate nominal failure strains in laminates containing local delaminates. The influence of edge delamination and matrix crack tip delmaination on laminate stiffness and strength was compared.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1984
Accession Number
ADA137737

Entities

People

  • T. K. O'brien

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Army Aviation
  • Boundary Value Problems
  • Composite Materials
  • Crack Tips
  • Cracks
  • Delamination
  • Epoxy Laminates
  • Equations
  • Failure Mode And Effect Analysis
  • Graphitic Materials
  • Laminates
  • Materials
  • Materials Laboratories
  • Materials Science
  • Mechanics
  • Micromechanics
  • Stiffness

Readers

  • Analytical Mechanics
  • Structural Health Monitoring of Composite Structures.