The Relationship between Tensile Strength and Flexure Strength in Fiber Reinforced Composites.

Abstract

Tensile data on unidirectional composites generated from a flexural test usually yield a higher strength than observed from a standard tensile coupon. According to a statistical strength theory based on a Weibull distribution, the presence of a stress gradient in the flexure test results in an apparent increase in tensile strength as compared to the tensile test under uniform stress. In the present paper this concept is explored by utilizing data from undirectional graphite-epoxy composite to compare with theoretical results generated from a two parameter Weibull distribution. A larger variation in tensile strength is observed from tensile coupon data than from flexure data. Such differences are not in accordance with strength theories based on a uniform flaw distribution and raise questions concerning variability of the test methods, as well as sources of material variability. (Author)

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Document Details

Document Type
Technical Report
Publication Date
Dec 01, 1980
Accession Number
ADA097033

Entities

People

  • James M. Whitney
  • Marvin Knight

Organizations

  • Wright Laboratory

Tags

DTIC Thesaurus Topics

  • Aeronautical Laboratories
  • Air Force
  • Composite Materials
  • Data Sets
  • Epoxy Composites
  • Failure Mode And Effect Analysis
  • Government Procurement
  • Governments
  • Graphite Epoxy Composites
  • Graphitic Materials
  • Materials
  • Materials Laboratories
  • Materials Testing
  • Mechanics
  • Standards
  • Tensile Strength
  • Test Methods

Readers

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