[Caractérisation et modélisation 3D des fissures courtes de fatigue de coin dans des alliages dʼaluminium à haute résistance]
La croissance des fissures courtes de fatigue est fortement influencée par un grand nombre de facteurs tels que la microstructure environnante, lʼétat de contrainte local, la forme des fissures. La tomographie haute résolution permet dʼimager la propagation des fissures dans des éprouvettes de fatigue au cours dʼessais in situ avec une résolution spatiale sub micronique et permet ainsi de visualiser les processus de propagation le long de la totalité du front de fissure (en surface et en volume). Dans ce travail, la croissance des fissures de fatigue a été caractérisée dans un alliage dʼaluminium à haute résistance élaboré par coulée continue ainsi que dans un alliage à grain fins élaboré par métallurgie des poudres. Ce dernier matériau constitue un matériau modèle qui présente des formes de fissures considérablement plus simples que dans lʼalliage à gros grains ce qui permet de séparer les effets purement mécaniques (variation de lʼétat de contrainte le long du front et fermeture induite par la plasticité) des effets purement microstructuraux (tels que les déflexions locales et la fermeture par rugosité). Pour les deux alliages, la croissance des fissures a été étudiée lors dʼessais cycliques à amplitude de contrainte constante, ponctués par des essais de surcharge (sur un cycle unique). Nous présentons ici un résumé des principaux résultats obtenus du point de vue expérimental. Une modélisation de la propagation 3D des fissures est également décrite ainsi que certains des résultats que cette approche simplifiée a permis dʼobtenir.
The growth of fatigue cracks at small length scales is known to be influenced by a variety of factors, including local microstructure, varying stress states and crack shape. High resolution computed tomography allows for sub-micron resolution imaging of failure processes in small test coupons undergoing in situ cyclic loading, providing detailed three-dimensional (3D) assessment of propagation processes across the entire crack front (surface and depth). In this work fatigue crack growth has been examined in an advanced Direct Chill (DC) cast aluminium alloy, along with a fine grained powder-metallurgy alloy. The latter is identified as a model material, offering considerably simpler microscopic crack paths than the DC cast alloy, and hence a means of separating bulk mechanical effects (such as stress state variations across a crack front and plasticity induced closure) from microstructural effects (such as crystallographic deflection and roughness induced crack closure). Crack growth has been studied in both materials under both constant amplitude (CA) and single peak overload (OL) conditions. Experimental results are presented in the present paper, particularly in relation to micromechanical understanding of failure. A modelling approach based on those results, and some typical results, is also presented.
Mot clés : Fatigue, Tomographie, Rayonnement synchrotron, Fermeture des fissures, Alliages dʼaluminium
Henry Proudhon 1 ; A. Moffat 2 ; Ian Sinclair 2 ; Jean-Yves Buffiere 3
@article{CRPHYS_2012__13_3_316_0,
author = {Henry Proudhon and A. Moffat and Ian Sinclair and Jean-Yves Buffiere},
title = {Three-dimensional characterisation and modelling of small fatigue corner cracks in high strength {Al-alloys}},
journal = {Comptes Rendus. Physique},
pages = {316--327},
publisher = {Elsevier},
volume = {13},
number = {3},
year = {2012},
doi = {10.1016/j.crhy.2011.12.005},
language = {en},
}
TY - JOUR AU - Henry Proudhon AU - A. Moffat AU - Ian Sinclair AU - Jean-Yves Buffiere TI - Three-dimensional characterisation and modelling of small fatigue corner cracks in high strength Al-alloys JO - Comptes Rendus. Physique PY - 2012 SP - 316 EP - 327 VL - 13 IS - 3 PB - Elsevier DO - 10.1016/j.crhy.2011.12.005 LA - en ID - CRPHYS_2012__13_3_316_0 ER -
%0 Journal Article %A Henry Proudhon %A A. Moffat %A Ian Sinclair %A Jean-Yves Buffiere %T Three-dimensional characterisation and modelling of small fatigue corner cracks in high strength Al-alloys %J Comptes Rendus. Physique %D 2012 %P 316-327 %V 13 %N 3 %I Elsevier %R 10.1016/j.crhy.2011.12.005 %G en %F CRPHYS_2012__13_3_316_0
Henry Proudhon; A. Moffat; Ian Sinclair; Jean-Yves Buffiere. Three-dimensional characterisation and modelling of small fatigue corner cracks in high strength Al-alloys. Comptes Rendus. Physique, Volume 13 (2012) no. 3, pp. 316-327. doi : 10.1016/j.crhy.2011.12.005. https://comptes-rendus.academie-sciences.fr/physique/articles/10.1016/j.crhy.2011.12.005/
[1] Propagation of short fatigue cracks, International Metals Reviews, Volume 29 (1984) no. 6, pp. 445-476
[2] The merging of fatigue and fracture mechanics concepts: a historical perspective, Progress in Aerospace Sciences, Volume 34 (1998) no. 5–6, pp. 347-390
[3] Stress intensity factor K and the elastic T-stress for corner cracks, International Journal of Fracture, Volume 109 (2001) no. 2, pp. 209-225
[4] Small fatigue cracks (I. Milne; R.O. Ritchie; B. Karihaloo, eds.), Comprehensive Structural Integrity, Pergamon, Oxford, 2003, pp. 129-164
[5] MicroComputed Tomography: Methodology and Applications, CRC, 2008
[6] Direct observation of crack opening as a function of applied load in the interior of a notched tensile sample of AlLi 2090, Acta Materialia, Volume 45 (1997) no. 5, pp. 1977-1987
[7] A 3D measurement procedure for internal local crack driving forces via synchrotron X-ray microtomography, Acta Materialia, Volume 52 (2004) no. 5, pp. 1305-1317
[8] The effect of fibre fractures in the bridging zone of fatigue cracked Ti6Al4V/SiC fibre composites, Acta Materialia, Volume 52 (2004) no. 6, pp. 1423-1438
[9] Three-dimensional visualization of the interaction between fatigue crack and micropores in an aluminum alloy using synchrotron X-ray microtomography, Metallurgical and Materials Transactions A, Volume 38 (2007) no. 8, pp. 1774-1785
[10] Fatigue crack growth and load redistribution in Ti/SiC composites observed in situ, Acta Materialia, Volume 57 (2009) no. 2, pp. 590-599
[11] Fatigue crack propagation: In situ visualization using X-ray microtomography and 3D simulation using the extended finite element method, Acta Materialia, Volume 54 (2006) no. 4, pp. 1111-1122
[12] Numerical modelling of combined roughness and plasticity induced crack closure effects in fatigue, Materials Science and Engineering A, Volume 291 (2000) no. 1–2, pp. 224-234
[13] Analytical and finite element modelling of roughness induced crack closure, Acta Materialia, Volume 52 (2004) no. 2, pp. 343-353
[14] High resolution X-ray tomography of micromechanisms of fatigue crack closure, Scripta Materialia, Volume 55 (2006) no. 1, pp. 47-50
[15] Roughness- and plasticity-induced fatigue crack closure under single overloads: Analytical modelling, Acta Materialia, Volume 54 (2006) no. 17, pp. 4405-4414
[16] Influence of grain structure and slip planarity on fatigue crack growth in low alloying artificially aged 2xxx aluminium alloys, International Journal of Fatigue, Volume 29 (2007) no. 5, pp. 869-878
[17] Finite element and analytical modelling of crack closure due to repeated overloads, Acta Materialia, Volume 56 (2008) no. 4, pp. 835-851
[18] Study of the interaction of a short fatigue crack with grain boundaries in a cast Al alloy using X-ray microtomography, Acta Materialia, Volume 51 (2003) no. 3, pp. 585-598
[19] 3d imaging in material science: Application of X-ray tomography, Comptes Rendus Physique, Volume 11 (2010) no. 9–10, pp. 641-649
[20] Three-dimensional visualisation of fatigue cracks in metals using high resolution synchrotron X-ray micro-tomography, Materials Science and Technology, Volume 22 (2006) no. 9, pp. 1019-1024
[21] Invited article: The fast readout low noise camera as a versatile X-ray detector for time resolved dispersive extended X-ray absorption fine structure and diffraction studies of dynamic problems in materials science, chemistry, and catalysis, Review of Scientific Instruments, Volume 78 (2007) no. 9, p. 091301
[22] The Image Processing Handbook, CRC Press, 1994
[23] Observation of microstructure and damage in materials by phase sensitive radiography and tomography, Journal of Applied Physics, Volume 81 (1997) no. 9, pp. 5878-5886
[24] Finite element analysis of plasticity-induced fatigue crack closure: An overview, Engineering Fracture Mechanics, Volume 71 (2004) no. 2, pp. 149-171
[25] Standard Test Method for Measurement of Fatigue Crack Growth Rates, Annual Book of ASTM Standards, vol. E647-95, ASTM, Philadelphia, 1995
[26] On crack closure in the near-threshold region, Scripta Metallurgica, Volume 15 (1981) no. 6, pp. 633-636
[27] Fatigue crack closure mechanism in titanium, Fatigue of Engineering Materials and Structures, Volume 1 (1979) no. 1, pp. 135-148
[28] Oxide-induced crack closure: an explanation for near-threshold corrosion fatigue crack growth behavior, Metallurgical Transactions. A, Physical Metallurgy and Materials Science, Volume 12 (1981) no. 8, pp. 1435-1443
[29] Investigation of crack closure and the propagation of semi-elliptical fatigue cracks in Q1N (HY80) pressure vessel steel, International Journal of Fatigue, Volume 17 (1995) no. 8, pp. 577-581
[30] Influence of through-thickness crack shape on plasticity induced crack closure, Fatigue and Fracture of Engineering Materials and Structures, Volume 31 (2008) no. 2, pp. 209-220
[31] Stress intensity factors for tunnelling corner cracks under mode i loading, Fatigue and Fracture of Engineering Materials and Structures, Volume 23 (2000) no. 1, pp. 81-90
[32] Fatigue of Materials, Cambridge University Press, Cambridge, 1994
[33] Analysis of closure in fatigue crack growth, Journal of Applied Mechanics Transactions ASME, Volume 45 (1978) no. 2, pp. 267-276
[34] Mechanisms of fatigue crack propagation in metals, ceramics and composites: Role of crack tip shielding, Materials Science and Engineering, Volume 103 (1988) no. 1, pp. 15-28
[35] Fatigue crack propagation and cryogenic fracture toughness behavior in powder metallurgy aluminum–lithium alloys, Metallurgical Transactions. A, Physical Metallurgy and Materials Science, Volume 22A (1991) no. 1, pp. 191-202
[36] 3D characterisation of the nucleation of a short fatigue crack at a pore in a cast al alloy using high resolution synchrotron microtomography, International Journal of Fatigue, Volume 27 (2005) no. 10, pp. 1215-1220
[37] Three-dimensional grain mapping by X-ray diffraction contrast tomography and the use of Friedel pairs in diffraction data analysis, Review of Scientific Instruments, Volume 80 (2009) no. 3, p. 033905
[38] 3-D growth of a short fatigue crack within a polycrystalline microstructure studied using combined diffraction and phase-contrast X-ray tomography, Acta Materialia, Volume 59 (2011) no. 2, pp. 590-601
[39] H. Proudhon, S. Forest, W. Ludwig, Large scale finite element simulations of polycrystalline aggregates: applications to X-ray diffraction and imaging for fatigue metal behaviour, in: N. Hansen, D. Juul Jensen, S.F. Nielsen, H.F. Poulsen, B. Ralph (Eds.), Challenges in Materials Science and Possibilities in 3D and 4D Characterization Techniques, 31st Risö International Symposium on Materials Science, Roskilde, Denmark, 2010, pp. 121–139.
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