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CLOSURE BEHAVIOUR OF SURFACE CRACKS
Author(s) -
Fleck N. A.,
Smith I. F. C.,
Smith R. A.
Publication year - 1983
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.1460-2695.1983.tb00339.x
Subject(s) - amplitude , crack closure , materials science , closure (psychology) , strain gauge , structural engineering , constant (computer programming) , composite material , mechanics , plane (geometry) , crack tip opening displacement , fracture mechanics , geometry , optics , mathematics , physics , engineering , market economy , computer science , economics , programming language
— The fatigue crack closure response was investigated for a surface crack in BS4360 50B structural steel, subjected to (1) constant amplitude loading and (2) constant amplitude loading interrupted by a single peak overload. A variety of compliance techniques was employed to determine closure behaviour. The crack mouth gauge measured the bulk, plane strain closure load, while the near tip strain gauge indicated the surface, plane stress closure response. For constant amplitude loading it was found that the surface regions of a surface crack are closed for a greater portion of the load cycle than the maximum depth point. A single peak overload caused different closure and growth rate transients at the surface of the thumbnail crack and at the maximum depth point. For growth rates above 10 ‐6 mm/cycle, such behaviour agrees with the response of a through crack when subjected to constant amplitude loading, and a single peak overload.