Accession Number:

ADA031071

Title:

Initial Development of a Fatigue-Crack-Retardation Model.

Descriptive Note:

Final rept. 18 Jun 74-31 Dec 75,

Corporate Author:

BATTELLE COLUMBUS LABS OHIO

Report Date:

1976-01-31

Pagination or Media Count:

123.0

Abstract:

A fatigue-crack-propagation model is developed by reducing crack-tip plasticity to a single pair of enlarged dislocations, termed superdislocations, whose response is equivalent to that of the aggregate plastic zone. The crack-tip damage or deformation and accompanying incremental crack advance resulting from each loading cycle are accumulated in a single super-superdislocation pair for residual interaction on the next loading cycle. Key features of this development are that the required material parameters are limited to the shear modulus, Poissons ratio, and tensile-yield strength, and that crack-surface closure is accommodated. A significant simulation of the fatigue-crack-propagation process along with a promising correlation with experimental results are achieved. Author

Subject Categories:

  • Metallurgy and Metallography
  • Crystallography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE