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The influence of cross‐sectional thickness on fatigue crack growth
Author(s) -
Guo W.,
Wang C. H.,
Rose L. R. F.
Publication year - 1999
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 - 10.1046/j.1460-2695.1999.00176.x
Subject(s) - crack closure , materials science , constraint (computer aided design) , paris' law , stress concentration , structural engineering , crack growth resistance curve , stress intensity factor , finite element method , deformation (meteorology) , crack tip opening displacement , composite material , fracture mechanics , mechanics , geometry , mathematics , engineering , physics
For thin structures, fatigue crack growth rates may vary with the structure's thickness for a given stress intensity factor range. This effect is mainly due to the change in the nature of the plastic deformation when the plastic zone size becomes comparable with, or greater than, the cross‐sectional thickness. Variations in the constraint affect both the crack tip plastic blunting behaviour as well as the fatigue crack closure level. Approximate expressions are constructed for the constraint factor based on asymptotic values and numerical results, which are shown to correlate well with finite element results. It is demonstrated that the present results not only permit predictions of the specimen thickness effects on fatigue crack propagation under spectrum loading, but also eliminate the need to determine the constraint factor by curve‐fitting crack growth data.