Journal Published Online: 31 October 2014
Volume 4, Issue 2

Characterization of Threshold Stress Intensity as a Function of Near-Tip Residual Stress: Theory, Experiment, and Applications



Threshold stress intensity, ΔKth, is not a material constant, but a variable that is extremely sensitive to load history. This effect has nothing to do with crack closure. It is associated with the influence of near-tip residual stress, σ*, on instantaneous resistance of crack tip surface layers to failure under atmospheric conditions. An analytical procedure is proposed to estimate σ* under constant amplitude loading as well as after tensile or compressive overloads. An experimental procedure is proposed to determine ΔKth under these loading conditions. ΔKth estimates obtained under a variety of overloads and underloads as well as under constant amplitude loading show an excellent correlation with computed σ*. The proposed experimental procedure and analytical relationships appear suitable for adoption as standard practice for an engineering application of threshold stress intensity under variable amplitude loading.

Author Information

Sunder, R.
BiSS (P) Ltd., Bangalore, IN
Pages: 26
Price: $25.00
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Stock #: MPC20140037
ISSN: 2165-3992
DOI: 10.1520/MPC20140037