Accession Number:

ADA261679

Title:

J and CTOD Estimation Equations for Shallow Cracks in Single Edge Notch Bend Specimens,

Descriptive Note:

Final rept.

Corporate Author:

ILLINOIS UNIV AT URBANA DEPT OF CIVIL ENGINEERING

Personal Author(s):

Report Date:

1993-01-01

Pagination or Media Count:

28.0

Abstract:

Results from two dimensional plane strain finite-element analyses are used to develop J and CTOD estimation strategies appropriate for application to both shallow and deep crack SEB specimens. Crack depth to specimen width aW ratios between 0.05 and 0.70 are modelled using Ramberg-Osgood strain hardening exponents n between 4 and 50. The estimation formulas divide J and CTOD into small scale yielding SSY and large scale yielding LSY components. For each case, the SSY components is determined by the linear elastic stress intensity factor, K sub I. The formulas differ in evaluation of the LSY component. The techniques considered include estimating J or CTOD from plastic work based on load line displacement A sub plILLD, from plastic work based on crack mouth opening displacement A sub plCMODpl, and from the plastic component of crack mouth opening displacement CMOd pl. A sub plCMOD provides the most accurate J estimation possible. CTOD estimates based on scalar proportionality of CTOD sub 1sy and CMOD pl are highly inaccurate, especially for materials with considerable strain hardening, where errors up to 38 occur.

Subject Categories:

  • Numerical Mathematics
  • Mechanics
  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE