PSI - Issue 57

Nesrine Majed et al. / Procedia Structural Integrity 57 (2024) 502–509

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Nesrine Majed et al. / Structural Integrity Procedia 00 (2019) 000 – 000

sensitive to small defects, and a second zone, for defect sizes between 550 μm and 900 μm , is qualified by a constant fatigue limit. 5.3 Comparison between A 356/A 357 based on affected depth For the load =−1 , Nasr et al (2018) indicated that the affected depth of the cast alloy A356 is = 280 μm . However, the affected depth of the cast alloy of the A 357 is = 35 0 μm . As a result, the aluminium A 356 will have a longer fatigue life than the other aluminium A 357. This result has been confirmed by Wang et al (2001). Since, the two alloys have close mechanical properties, we can conclude that the factor / influences the affected depth. 6. Conclusion In this paper, surface semi-spherical voids were analyzed using FE calculations to determine stress distributions around defects. The affected depth approach was employed to predict the high-cycle fatigue (HCF) of A357-T6 alloy, which contains surface defects and is subjected to tension at load ratios of = -1 and = 0.1. This analysis allowed for the creation of Kitagawa-Takahashi diagrams for the defective materials. Comparing the computed HCF strength with experimental results revealed a strong agreement for the tested material. The defect has been modeled by a surface spherical void. It will be interesting to evaluate fatigue life of complex defect. In this work, microstructure described by SDAS has been studied with one mean value. Some perspectives of this study are to validate the AD approach for defective materials subjected to cyclic loading by considering the SDAS effect. Ashby M. F., Jones D. R. H. Engineering materials2: an introduction to microstructures, processing and design. Butter worth-Heinemann, fourth édition, 2013. Bailon, J.-P., Dorlot J.-M. Des matériaux. Presses internationales Polytechnique, 2002. Q.G. Wang., D. Apelian, D.A. Lados. Fatigue behavior of A356/357 aluminium cast alloys. Part II -Effect of microstructural constituents. Journal of Light Metals 1 (2001) 85-97 Iben Houria, M., I, Nadot, Y., Fathallah, R., Roy, M., &Maijer, D. M. (2015). Influence of casting defect and SDAS on the multiaxial fatigue behaviour of A356-T6 alloy including mean stress effect. International Journal of Fatigue, 80, 90-102 Y. Murakami, Metal Fatigue: Effects of Small Defects and Non-metallic Inclusion, Elsevier Science Ltd, Oxford, UK, 2002. I. Serrano-Munoz, J.-Y. Buffiere, C. Verdu, Y. Gaillard, P. Mu, Y. Nadot, Influence of surface an internal casting defects on the fatigue behaviour of A357-T6 cast aluminium alloy, Int. J. Fatig. (2015), Y. Nadot., T. Billaudeau, Multiaxial fatigue limit criterion for defective materials, Eng. Fract. Mech. 73 (2006) 112 – 133. Gadouini, "Influence des défauts sur la tenue en fatigue des métaux soumis à des sollicitations cycliques multiaxiales: Application aux ressorts de suspension automobile," Rapport de Thèse, Poitiers, 2007. A., Nasr., W.Hassine., C.Bouraoui. Affected depth approach to determine the fatigue strength of materials containing surface defects, Elsevier,2018 POLMEAR I.J. 2007 Light alloys: from traditional alloys to nanocrystals Elsevier, Butterworth-Heinemann, Amsterdam. Serrano-Munoz I., Influence of casting defects on the fatigue behaviour of an A357-T6 aerospace alloy, PhD Thesis INSA de Lyon; 2014. I. Serrano-Munoz., D. Shiozawa., S. Dancette., C. Verdu., J.-Y. Buffiere, Torsional fatigue mechanisms of an A357-T6 cast aluminium alloy, Acta Materialia (2020) A.Rotella., Y.Nadot., S.Réchard :Fatigue life of cast Al component, Elsevier ( 2015 ) 211 – 222 J.Lemaitre., J.-L.Chaboche., A.Benallal, R. Desmorat, Mécaniques des matériaux solides-3ème édidtion, Dunod,2009 A.Rotella., Y.Nadot., M.Piellard., R.Augustin, Influence of defect morphology and position on the fatigue limit of cast Al alloy: 3D characterization by X-ray microtomography of natural and artificial defects. Le Pen, E., Baptiste, D: Prediction of the fatigue-damaged behaviour of Al/Al2O3 composites by a micro-macro approach. Compos. Sci. Technol. 61(15), 2317 – 2326 (2001) P. Mu., Y. Nadot., C. Nadot-Martin., Chabod A., Serrano-Munoz I., Verdu C. Influence of casting defects on the fatigue behavior of cast aluminum AS7G06-T6. International Journal of Fatigue,63(2014)97-109 A.Nasr., W.Hassine., C.Bouraoui.. High cycle fatigue approach based on affected depth and considering the secondary dendrite arming spacing (SDAS) effect for a defective A356-T6 alloy. The International Journal of Advanced Manufacturing Technology. A.Nasr ., W. Hassine ., C. Bouraoui .Fatigue limit assessment for defective materials based on affected depth . Met. Res. Technol. 114 (2017), article no. 505. References