Accession Number:

ADA261591

Title:

Approximate Techniques for Predicting Size Effects on Cleavage Fracture Toughness (Jc)

Descriptive Note:

Final rept.

Corporate Author:

ILLINOIS UNIV AT URBANA DEPT OF COMPUTER SCIENCE

Personal Author(s):

Report Date:

1993-01-01

Pagination or Media Count:

40.0

Abstract:

This investigation examines the ability of an elastic T-stress coupled with a modified boundary layer MBL solution to predict stresses ahead of a crack tip in a variety of planar geometries. The approximate stresses are used as input to estimate the effective driving force for cleavage fracture JO using the micromechanically based approached introduced by Dodds and Anderson. Finite element analyses for a wide variety of planar cracked geometries are conducted which have elastic biaxiality parameters B ranging from -0.99 very low constraint to 2.96 very high constraint. The magnitude and sign of B indicate the rate at which crack-tip constraint changes with increasing applied load. All results pertain to a moderately strain hardening material strain hardening exponentn of 10. These analyses suggest that B is an effective indicator of both the accuracy of T-MBL estimates of Jo and of applicability limits on evolving fracture analysis methodologies i.e. T-MBL, J-Q, and JIJO.. .. Elastic-plastic fracture mechanics, Size effects, Finite element analysis modified boundary layer, T-stress, Jssy, Jo Q, Structural integrity assessment.

Subject Categories:

  • Numerical Mathematics
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE