DISCUSSION OF "UNUSUAL POTENTIAL DROP DURING THE APPLICATION OF THE ELECTRICAL POTENTIAL METHOD IN A FRACTURE MECHANICS TEST - DISCUSSION

Fatigue cracks were produced by tension-tension cycling at R=0.1, where R is the ratio of minimum to maximum loads. Portions of these cracks would likely be closed at zero load. This would account for the initial rise in electrical potential as the crack first opens on subsequent test loading. For the two materials with coarse fatigue crack surfaces, the initial rise in potential was followed by a precipitous drop, which may be the result of recontact of the coarse fatigue crack surface facets. No drop in potential was experienced by the material with relatively smooth fatigue crack surfaces, supporting the "recontact' thesis. For the beryllium tested, the potential did not initially rise, but instead immediately decreased to a minimum value and then rose smoothly until discontinuous jumps were produced by cracking. In order for the unique behavior of beryllium to be explained, more research is needed to be done.

  • Supplemental Notes:
    • This article was originally published in the Journal of Testing and Evaluation, JTEVA, Volume 4, Number 4, July 1976, pp 257-260.
  • Corporate Authors:

    American Society for Testing and Materials

    100 Barr Harbor Drive, P.O. Box C700
    West Conshohocken, PA  United States  19428-2957
  • Authors:
    • BACHMANN, V
    • Munz, D
  • Publication Date: 1976-11

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Filing Info

  • Accession Number: 00148426
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Mar 15 1977 12:00AM