Abstract
The role of tensile overload superimposed on a constant amplitude cycling results in compressive residual stresses at the crack tip that cause crack growth retardation. The degree to which this effect manifests depends on whether the tests are done at a constant driving force (Kmax) or at a constant crack growth rate (da/dN). It is observed that depending on the magnitude of the overload at a given applied base stress intensity, these residual stresses can have significant effect on the crack growth in both the inert (vacuum) and the chemical (NaCl) environments. In general, cracks will grow only if the total crack tip driving force Ktotal exceeds the long crack intrinsic threshold
Acknowledgments
AKV would like to thank Dr. Eun Lee, NAVAIR (retired) for helpful technical discussions. Thanks to Dr. N. Apetre (NRL) for increasing the resolution of the figures.
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Article note
AKV dedicates this article to a dear friend, Prof. David Quesnel, University of Rochester, NY, who passed away in early 2018. David was an excellent teacher and was a leading scientist in the area of adhesion and stress corrosion science.
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