Measurement of the J Integral with Caustics: An Experimental and Numerical Investigation

Abstract

The optical method of caustics as applied to the measurement of the J integral in plastically deforming materials was studied numerically and experimentally. The numerical calculations modeled a cracked body loaded under Mode I, plane stress, small scale yielding conditions. The results were used to generate simulated optical patterns for caustics obtained from both inside and outside the crack tip plastic zone. These caustics were compared with corresponding caustics observed experimentally. In addition, the region of dominance of the plane stress, HRR field was investigated, and the effect of plasticity on the accuracy of caustics from the elastic region outside the plastic zone was determined. The extent of the region of three dimensionally near the crack tip and its effect ont he method of caustics was also investigated. Keywords: elastic-plastic fracture; finite elements.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1986
Accession Number
ADA177273

Entities

People

  • Alan T. Zehnder
  • Ares J. Rosakis
  • R. Narasimhan

Organizations

  • California Institute of Technology

Tags

DTIC Thesaurus Topics

  • Accuracy
  • Cameras
  • Crack Tips
  • Cracks
  • Diameters
  • Elastic Materials
  • Equations
  • Fracture (Mechanics)
  • Geometry
  • Integrals
  • J Integrals
  • Materials
  • Measurement
  • Mechanics
  • Plastic Properties
  • Stress Intensity Factors
  • Three Dimensional

Readers

  • Materials Science (Mechanical Engineering).
  • Wave Propagation and Nonlinear Chaotic Dynamics.