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Fatigue Crack Growth from Small Surface Cracks in Transformation‐Toughened Ceramics
Author(s) -
Andreasen Jens H.,
Moller Carsten V.,
Karihaloo Bhushan L.
Publication year - 1995
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1995.tb08815.x
Subject(s) - materials science , crack closure , stress intensity factor , paris' law , composite material , crack growth resistance curve , fracture toughness , scanning electron microscope , growth rate , ceramic , stress concentration , toughness , power law , fracture mechanics , geometry , mathematics , statistics
A theoretical model based on the theory of complex potentials and dislocation formalism is used to simulate the fatigue crack growth of small cracks in a transformation‐toughened ceramic. Assuming power‐law crack growth in which the growth rate depends on the effective stress intensity at the crack tip instead of the applied stress intensity, it is shown that the crack growth rate decreases with the applied stress intensity in the initial stage of fatigue crack growth. This is in agreement with existing experimental evidence for the growth of small cracks in Mg‐PSZ. New experimental results obtained by in situ observation in a scanning electron microscope of a similar material confirm this behavior. The numerical results also confirm the plausibility of using the steady‐state toughness value obtained from quasi‐static crack growth as a normalizing parameter in the power‐law for fatigue crack growth.