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Experimental Mechanics

, Volume 18, Issue 12, pp 441–448 | Cite as

Classification of stress-intensity factors from isochromatic-fringe patterns

Isochromatic fringes corresponding to different combinations of KI, KII and σox have been constructed, and the unique characteristics of the isochromatics can be used to classify the state of stress (KI, KII and σox) at the crack tip
  • J. W. Dally
  • R. J. Sanford
Article

Abstract

The stresses in the local neighborhood of a crack tip have been used to develop a relation between the isochromatic-fringe orderN, its position parametersr and θ and the stress field expressed in terms of stress intensities,K I ,K II , and a far-field stress σ ox . This relation was programmed and a plotting routine was developed to map isochromatic (σ1 − σ2) fields in the neighborhood of the crack tip.

The stress intensitiesK I andK II and the far-field stress σ ox were varied and isochromatic fields were constructed for each combination. As bothK II and σ ox influence the size, shape and orientation of the isochromatics loops in a systematic manner, the pictorial representation of the isochromatic fields can be used to classify the state of stress (K I ,K II and σ ox ) at the crack tip. Isochromatics which classify six different states of stress have been illustrated and methods used to determineK I ,K II , andσ ox in five of the six states are given.

Keywords

Mechanical Engineer Fluid Dynamics Stress Intensity Stress Field Local Neighborhood 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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Copyright information

© Society for Experimental Mechanics, Inc. 1978

Authors and Affiliations

  • J. W. Dally
    • 1
  • R. J. Sanford
    • 2
  1. 1.University of MarylandCollege Park
  2. 2.Structural Reliability Section, Ocean Technology DivisionNoval Research LaboratoryWashington

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