Controlled Crack Growth Specimen for Brittle Systems

Abstract

A pure Mode I fracture specimen and test procedure has been developed which provides extended, stable, through-thickness crack growth in ceramics and other brittle, nonmetallic materials. Fixed displacement loading, applied at the growth mouth, promotes stable crack extension by reducing the stored elastic strain energy. Extremely fine control of applied displacements is achieved by utilizing the Poisson's expansion of a compressively loaded cylindrical pin. Stable cracks have been successfully grown in soda-lime glass and monolithic Al203 for lengths in excess of 20 mm without uncontrollable catastrophic failure.

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Document Details

Document Type
Technical Report
Publication Date
May 01, 1990
Accession Number
ADA227150

Entities

People

  • Anthony M. Calomino
  • David N. Brewer

Organizations

  • National Aeronautics and Space Administration

Tags

DTIC Thesaurus Topics

  • Army Aviation
  • Axial Loads
  • Bulk Modulus
  • Ceramic Materials
  • Closed Loop Systems
  • Crack Propagation
  • Crack Tips
  • Cracks
  • Damage Tolerance
  • Diameters
  • Displacement
  • Far Field
  • Geometry
  • Materials
  • Stresses
  • Thickness
  • Thin Films

Readers

  • Materials Science (Mechanical Engineering).
  • Mechanical Engineering/Mechanics of Materials.