Open AccessTHE OPPOSITE SIGN DISLOCATIONS AT A CRACK TIP AND THE IMAGE FORCE THEORY OF DISLOCATION-FREE ZONE
Author(s) -
Long Qiwei,
Xiong Liangyue
Publication year - 1984
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.33.755
Subject(s) - dislocation , materials science , sign (mathematics) , crack tip opening displacement , condensed matter physics , plane (geometry) , slip (aerodynamics) , mechanics , geometry , crack closure , composite material , fracture mechanics , physics , mathematical analysis , mathematics , thermodynamics
The dislocation distribution function in the plastic zone at a crack tip is calculated with the help of a modified BCS-type crack model. It is found that opposite sign dislocations appear on the slip plane immediately ahead of the crack tip. These negative dislocations seem to enter the crack tip and blunt it, resulting in a dislocation-free zone at the crack tip. The image force theory of the formation of dislocation-free zone is discussed.