Characterization of Delamination Onset and Growth in a Composite Laminate.

Abstract

The onset and growth of delaminations in unnotched graphite-epoxy laminates is described quantitatively. These laminates, designed to delaminate at the edges under tensile loads, were tested and analyzed. Delamination growth and stiffness loss were monitored nondestructively. Laminate stiffness decreased linearly with delamination size. The strain energy release rate, G, associated with delamination growth, was calculated from two analyses. A critical G for delamination onset was determined, and then was used to predict the onset of delaminations in laminates. A delamination resistance curve (R-curve) was developed to characterize the observed stable delamination growth under quasi-static loading. A power law correlation between G and delamination growth rates in fatigue was established. (MM)

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1981
Accession Number
ADA303920

Entities

People

  • T. K. O'brien

Organizations

  • Langley Research Center

Tags

DTIC Thesaurus Topics

  • Composite Materials
  • Delamination
  • Elastic Properties
  • Epoxy Laminates
  • Failure Mode And Effect Analysis
  • Fatigue Tests (Mechanics)
  • Finite Element Analysis
  • Graphitic Materials
  • Laminates
  • Materials
  • Materials Testing
  • Mechanics
  • Numerical Analysis
  • Photographs
  • Regression Analysis
  • Three Dimensional
  • X Rays

Fields of Study

  • Materials science

Readers

  • Materials Science (Mechanical Engineering).
  • Structural Health Monitoring of Composite Structures.