Journal article
Effect of underloads or overloads in fatigue crack growth by crack-tip blunting
Crack-tip blunting under tensile loads and re-sharpening of the crack-tip during unloading is one of the basic mechanisms for fatigue crack growth in ductile metals. Here, based on an elastic-perfectly plastic material model, crack growth computations are continued up to 700 full cycles by using re-meshing at several stages of the plastic deformation.
A compressive underload in one of the cycles tends to increase the rate of cyclic crack growth, and this effect is studied in detail for a single underload, based on the blunting re-sharpening mechanism. Subsequently, the increased rate of crack growth due to periodically occurring underloads is analysed.
A single overload has the opposite effect of giving a significant delay in the subsequent fatigue crack growth. An analysis is carried out to compare the effect of a small overload to that of a larger overload.
Language: | English |
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Year: | 2006 |
Pages: | 869-879 |
ISSN: | 18737315 and 00137944 |
Types: | Journal article |
DOI: | 10.1016/j.engfracmech.2005.10.009 |