In situ characterization of the fatigue crack-tip stress fields

Soo Yeol Lee, E-Wen Huang, Wanchuck Woo

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

A neutron diffraction technique was used to directly measure residual stress fields around a fatigue-crack tip at the mid-thickness and near the surface of the compact-tension specimen, where the fatigue crack was grown with a R-ratio of 0.1 under a load control mode. The stress mapping was conducted as a function of distance from the crack tip with 1-mm spatial resolution of neutron beam along the crack-propagation direction. The residual strain fields near the surface were much more significant than those at the mid-thickness. The evolution of the residual stress fields was examined in situ under applied load, in order to investigate the distribution of stresses in the vicinity of the crack tip. The three orthogonal stress components (i.e., crack growth, crack opening, and through thickness) of the specimen under loading were calculated from the directly-measured three orthogonal strain components without any assumptions of a plane strain or plane stress condition. A clear distinction for the evolution of the crack-tip stress field was observed along the direction of the through-thickness of the sample, which might account for the intrinsic differences of a crack-opening process and resultant crack-tip driving force between at the mid-thickness and near the surface.

Original languageEnglish
Title of host publication8th Australasian Congress on Applied Mechanics, ACAM 2014, as Part of Engineers Australia Convention 2014
EditorsRaj Das, Sabu John
PublisherEngineers Australia
Pages624-628
Number of pages5
ISBN (Electronic)9781922107350
StatePublished - 1 Nov 2014
Event8th Australasian Congress on Applied Mechanics, ACAM 2014, as Part of Engineers Australia Convention 2014 - Melbourne, Australia
Duration: 25 Nov 201426 Nov 2014

Publication series

Name8th Australasian Congress on Applied Mechanics, ACAM 2014, as Part of Engineers Australia Convention 2014

Conference

Conference8th Australasian Congress on Applied Mechanics, ACAM 2014, as Part of Engineers Australia Convention 2014
CountryAustralia
CityMelbourne
Period25/11/1426/11/14

Keywords

  • Crack tip
  • Fatigue crack growth
  • Neutron diffraction
  • Stress field

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  • Cite this

    Lee, S. Y., Huang, E-W., & Woo, W. (2014). In situ characterization of the fatigue crack-tip stress fields. In R. Das, & S. John (Eds.), 8th Australasian Congress on Applied Mechanics, ACAM 2014, as Part of Engineers Australia Convention 2014 (pp. 624-628). (8th Australasian Congress on Applied Mechanics, ACAM 2014, as Part of Engineers Australia Convention 2014). Engineers Australia.