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

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:523

Article

Liljedahl, C. D. M.¹  Fitzpatrick, M. E.¹  Edwards, L.¹ 

[1] Open Univ, Milton Keynes MK7 6AA, Bucks, England

关键词: Residual stresses;    Neutron diffraction;    Finite element analysis;    Fatigue;    Crack retarders;    Hybrid structures;   

DOI  :  10.1016/j.msea.2009.06.024

来源: Elsevier

【 摘 要 】

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. (C) 2009 Elsevier B.V. All rights reserved.

【 授权许可】

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