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  United States  10016-5990
  • Authors:
    • Davidson, D L
    • Lankford Jr, J
  • Publication Date: 1976-1

Media Info

Subject/Index Terms

Filing Info

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