PLASTIC DISTRIBUTION AT THE TIPS OF PROPAGATING FATIGUE CRACKS

The techniques of selected area electron channeling and positive replica examination have been used to study the plastic zones attending fatigue crack propagation in 304 SS,6061-T6 aluminum alloy, and Fe-3Si steel. These observations allowed the strain distribution at the crack tip to be determined. The results indicate that the concepts of a monotonic and a cyclic plastic zone are essentially correct, with the strains at demarcation between these two zones being 3 to 6 percent. Strain distribution varies as r-1/2 in the cyclic zone and as ln r in the monotonic plastic zone. The strain distributions for all materials studied may be made approximately coincident by using a dimensionless parameter related to distance from the crack tip.

  • Supplemental Notes:
    • Presented at the Conference on Micromechanical Modelling of Flow and Fracture, Troy, N.Y., June 23-25, 1975.
  • Corporate Authors:

    American Society of Mechanical Engineers

    Two Park Avenue
    New York, NY  USA  10016-5990
  • Authors:
    • Davidson, D L
    • Lankford Jr, J
  • Publication Date: 1976-1

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Filing Info

  • Accession Number: 00138343
  • Record Type: Publication
  • Source Agency: American Society of Mechanical Engineers
  • Files: TRIS
  • Created Date: Aug 11 1976 12:00AM