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THE VARIATION OF CRACK OPENING STRESS INTENSITY WITH TIME
Author(s) -
Lei Ming jun,
Yu Weikang,
Gerberich W. W.
Publication year - 1985
Publication title -
fatigue and fracture of engineering materials and structures
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.887
H-Index - 84
eISSN - 1460-2695
pISSN - 8756-758X
DOI - 10.1111/j.1460-2695.1985.tb00421.x
Subject(s) - materials science , asperity (geotechnical engineering) , crack closure , creep , substructure , relaxation (psychology) , residual stress , stress relaxation , plasticity , composite material , stress intensity factor , forensic engineering , metallurgy , mechanics , structural engineering , fracture mechanics , engineering , psychology , social psychology , physics
It was found that crack opening stress intensities are not constant after holding for various times in the unloaded state for iron and a sequence of Fe‐Si binary alloys. The crack opening level decreased with time first because of asperity creep and substructure relaxation, and then increased again with time due to reverse plastic zone relaxation allowing a new set of asperities to come into contact. It is demonstrated that the crack closure phenomenon is not only a result of residual plasticity, oxidation and asperities, but also is due to asperity creep and reverse plastic zone relaxation at the crack tip for low strength materials.