Evolution of residual stresses with fatigue crack growth in integral structures with crack retarders

C. D M Liljedahl, M. E. Fitzpatrick, L. Edwards

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Bonded straps are investigated for their ability to retard a growing fatigue crack in metallic structures. The evolution of the residual stresses in the vicinity of the strap with fatigue crack growth has been studied. Cracks were grown in single edge-notched tension (SEN(T)) specimens reinforced with either a titanium or a carbon fibre reinforced plastics (CFRP) strap. The residual stress evolution has been measured in situ during crack growth using neutron diffraction, and modelled with a finite element approach. The peak residual stresses induced by the mismatch of the coefficient of thermal expansion between the strap and plate materials were seen to be fairly constant with crack growth. Good correlation between the experimental and the modelling results was found, except at very long crack lengths for a specimen that exhibited considerable fracture surface roughness at long crack lengths. The difference was attributed to wedging of the fracture surface changing the expected stress state, rather than any effect of the strap.

Original languageEnglish
Pages (from-to)152-159
Number of pages8
JournalMaterials Science and Engineering A
Volume523
Issue number1-2
DOIs
Publication statusPublished - 15 Oct 2009
Externally publishedYes

Keywords

  • Crack retarders
  • Fatigue
  • Finite element analysis
  • Hybrid structures
  • Neutron diffraction
  • Residual stresses

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering
  • Mechanics of Materials

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