Prediction of Fiber/Matrix Interphase Properties and Their Influence on Interface Stress, Displacement and Fracture Toughness of Composite Material

Abstract

An elastic shear lag analysis, which includes an interphase region, has been developed and correlated with Mandell's micro-debonding test data 1 to determine the thickness and material properties of the interphase. The shear strength and the relationship between thickness and shear modulus of interphase were determined for both glass/epoxy and graphite/epoxy composites. An axisymmetric finite element model, which includes the interphase properties obtained from the shear lag analysis, was also developed. The effects of the interphase on stresses and deformation at the interface and fracture toughness of the fibrous composites were investigated. The following conclusions were drawn from the study: (1) By including an interphase, both the shear lag analysis and finite element model provide very good predications. (2) An interphase exists and is softer than the matrix. (3) The interphase has significant effect on stress concentration displacement and fracture toughness of the fibrous composite.

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Document Details

Document Type
Technical Report
Publication Date
Jan 03, 1990
Accession Number
ADA233616

Entities

People

  • Annete M. Arocho
  • Hsi C. Tsai
  • Lee W. Gause

Organizations

  • Naval Air Warfare Center Warminster

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Axial Loads
  • Axisymmetric
  • Composite Materials
  • Elastic Properties
  • Epoxy Composites
  • Finite Element Analysis
  • Graphitic Materials
  • Materials
  • Military Research
  • Modulus Of Elasticity
  • Security
  • Shear Modulus
  • Shear Strength
  • Shear Stresses
  • Stress Concentration
  • Thickness
  • Two Dimensional

Readers

  • Computational Fluid Dynamics (CFD)
  • Structural Dynamics.
  • Structural Health Monitoring of Composite Structures.