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Generically Dependent Continuant
RDF description of Cold hole expansion effect on the fatigue crack growth in welds of a 6061-T6 aluminum alloy - http://orbis.uaslp.mx/vivo/individual/scopus3883
Article
Compact test specimens were extracted from a 6061-T6 aluminum alloy welded plate with a thickness of 9 mm to analyze the cold hole expansion effect on fatigue crack growth tests conducted in mode I cyclic loading. At R = 0.1, a sharp crack in base metal, weld metal and heat affected zone was propagated from 17 to 24 mm. The fatigue crack growth at 24 mm (α = a/W = 0.3) was delayed by drilling a hole at the crack tip and applying a cold hole expansion of 4.1%25. The residual stress fields due to cold hole expansion were determined with the finite element method. The fatigue crack growth testing was continued up to a crack length of 35 mm (α ∼ 0.43) at the same R, and crack opening displacements of the post-expansion crack were also determined with the finite element method. The results were expressed in terms of crack length versus number of cycles, as well as, fatigue crack growth rate as a function of applied and effective stress intensity factor range. The cold hole expansion contributed to delay the fatigue crack growth in base metal, and to a lesser extent in the weld metal and heat affected zone. A crack closure effect was determined by means of load versus crack opening displacement curves of the post-expansion crack, which was, completely or partially closed, in welded zones with compressive residual stress fields. The fracture surfaces of each welded zone were analyzed to elucidate the crack nucleation zone and its relation with the residual stress field. In all cases the crack was initiated at the surface of the specimen where the residual stresses were positive. © 2014 Elsevier B.V.
6061-T6; Cold hole expansion; Fatigue crack growth; Finite element simulation; Welding Crack tips; Expansion; Fatigue crack propagation; Finite element method; Heat affected zone; Residual stresses; Stress intensity factors; Welded steel structures; Welding; Aluminum; Aluminum alloys; Crack tips; Cracks; Fatigue crack propagation; Finite element method; Heat affected zone; Metals; Residual stresses; Stress intensity factors; Stresses; Welded steel structures; Welding; Welds; 6061-T6; Cold hole expansion; Compressive residual stress; Crack opening displacement curves; Crack opening displacements; Effective stress intensity factor range; Fatigue-crack-growth tests; Finite element simulations; Cracks; Crack closure
Cold hole expansion effect on the fatigue crack growth in welds of a 6061-T6 aluminum alloy
Consejo Nacional de Ciencia y Tecnología, CONACYT: CB177834
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Journal of Materials Processing Technology