Open AccessOn DIC measurements of DeltaKeff to verify if it is the FCG driving force
Author(s) -
Jorge A. González,
Jaime Tupiassú Pinho de Castro,
G. L. G. Gonzáles,
Marco Antônio Meggiolaro,
José Luiz de França Freire
Publication year - 2017
Publication title -
frattura ed integrità strutturale
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.368
H-Index - 19
ISSN - 1971-8993
DOI - 10.3221/igf-esis.41.31
Subject(s) - paris' law , materials science , digital image correlation , strain gauge , structural engineering , crack closure , stress intensity factor , composite material , crack growth resistance curve , fracture mechanics , engineering
Redundant data obtained under quasi-constant { delta K, Kmax} loading conditions is used to verify if the effective stress intensity factor (SIF) range delta Keff delta Kmax delta Kop is indeed the fatigue crack driving force. The crack opening SIF Kop is measured along the entire crack path on DC(T) low carbon steel specimens by a series of strain gages bonded along the crack paths, by a strain gage bonded on their back faces, and by a digital image correlation technique. All such measurements showed a significant Kop decrease as the crack sizes increased, while the fatigue crack growth rates remained essentially constant both in the thin and thick specimens, a behavior that cannot be explained by delta Keff arguments