The Shearing Contribution in Transformation Toughening of Brittle Materials,

Abstract

A simple constitutive law is proposed for the description of a ceramic composite which undergoes stress induced martensitic transformation. This law is used in finite element calculations to investigate the shear effect on the transformation zone near a crack tip. A formula describing the stress intensity factor change due to the shear contribution of the transformation is given. Significant loss of toughness is observed in the case of a stationary crack and is attributed entirely to the shear component of the transformation is given. Significant loss of toughness is observed in the case of a stationary crack and is attributed entirely to the shear component of the transformation. As the crack grows, the wake of the transformed material left behind the crack constitutes a source of toughening. This toughening is due to both dilatancy and shear in the phase change and rises to a maximum level just after a propagation comparable with the zone height. Finally, it is shown that the shear component can be important when prediction of the fracture toughness of the transformation toughened ceramics are made.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 1985
Accession Number
ADA154656

Entities

People

  • P. Sofronis
  • R. M. Mcmeeking

Organizations

  • University of Illinois Urbana–Champaign

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Applied Mechanics
  • Boundaries
  • Boundary Value Problems
  • Ceramic Matrix Composites
  • Composite Materials
  • Crack Propagation
  • Crack Tips
  • Cracks
  • Equations
  • Finite Element Analysis
  • Materials
  • Mechanics
  • Modulus Of Elasticity
  • Shear Modulus
  • Shear Stresses
  • Stress Intensity Factors
  • Stresses

Fields of Study

  • Engineering

Readers

  • Mechanical Engineering/Mechanics of Materials.
  • Powder metallurgy of Titanium alloys.
  • Structural Health Monitoring of Composite Structures.