Fracture Toughness of Fibrous Composite Materials.

Abstract

Laminates with various proportions of 0 deg, + or - 45 deg, and 90 deg plies were fabricated from T300/5208 and T300/BP-907 graphite/epoxy prepreg tape material. The fracture toughness of each laminate orientation or lay-up was determined by testing center-cracked specimens, and it was also predicted with the general fracture-toughness parameter. The predictions were good except when crack-tip splitting was large, at which time the toughness and strengths tended to be underpredicted. By using predictions, a parametric study was also made of factors that influence fracture toughness. Fiber and matrix properties as well as lay-up were investigated. Without crack-tip splitting, fracture toughness increases in proportion to fiber strength and fiber volume fraction, increases linearly with E22/E11, is largest when the modulus of non-0 deg fibers is greater than that of O deg fibers. (MM)

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Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1984
Accession Number
ADA304703

Entities

People

  • C. C. Poe Jr

Organizations

  • Langley Research Center

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Composite Materials
  • Crack Tips
  • Delamination
  • Epoxy Laminates
  • Graphitic Materials
  • Laminates
  • Materials
  • Materials Processing
  • Materials Testing
  • Mechanical Working
  • Mechanics
  • Modulus Of Elasticity
  • Notch Sensitivity
  • Strain Gages
  • Stress Strain Relations
  • Stresses
  • Tensile Strength

Fields of Study

  • Materials science

Readers

  • Materials Science (Mechanical Engineering).
  • Mathematics or Statistics
  • Reinforced Composite Materials