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U.S. Department of Energy
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The Paris law for fatigue crack growth in terms of the crack tip opening displacement

Conference ·
OSTI ID:293054
 [1]
  1. Massachusetts Inst. of Tech., Cambridge, MA (United States)
A reference Paris law for K-valid fatigue cracks, with the threshold rate at the Burgers vector b and a threshold range of stress intensity E{radical}(2b), is compared with data from the literature. The faster growth rates of microstructurally short or highly loaded cracks, not K-valid, are compared with the crack tip displacement {Delta}CTOD from: alternating slip on one or two planes, J-mechanics (uncertain for shallow cracks), and the continuum sliding off from fans at a non-hardening plastic crack tip (predicting striated branch cracks). Low rates arise from roughening, closure, and obstacles requiring polyslip., In harder alloys, the smaller {Delta}CTOD for a given {Delta}K appears to be offset by reductions in roughening and resistance to polyslip. 48 refs., 8 figs., 6 tabs.
OSTI ID:
293054
Report Number(s):
CONF-970980--; ISBN 0-87339-382-1
Country of Publication:
United States
Language:
English