Biaxial Tensile Fracture of ATJ-S Graphite.

Abstract

Failure strains were measured in specimens of ATJ-S graphite fractured in biaxial tension using a test method that relies on the centrifugal forces produced by rotation to induce the desired stresses. The results are presented in terms of the cumulative probability of fracture versus maximum principal strain, and are compared to similar data for ATJ-S in uniaxial tension. The comparison shows that, at a given level of strain, the fracture probability is somewhat larger in biaxial tension than in uniaxial tension. An exploratory biaxial test on a specimen of carbon-carbon composite was conducted in the same test fixtures to demonstrate the wider applicability of the rotational method. Stress calculations using elastic and two nonlinear constitutive formulations, are presented for rotating bodies in the form of circular disks and slender bars. The predicted strains are compared to those measured on rotating specimens of ATJ-S and the validity of the various assumed stress-strain laws is discussed.

Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1975
Accession Number
ADA013166

Entities

People

  • Julius Jortner

Tags

DTIC Thesaurus Topics

  • Carbon Carbon Composites
  • Centrifugal Force
  • Composite Materials
  • Fiber Reinforced Composites
  • Graphitic Materials
  • Materials
  • Materials Testing
  • Probability
  • Reinforced Plastics
  • Rotation
  • Test Fixtures
  • Test Methods

Readers

  • Mechanical Engineering/Mechanics of Materials.