PSI - Issue 5

Amal ben Ahmed et al. / Procedia Structural Integrity 5 (2017) 524–530 Amal ben Ahmed et al. / Structural Integrity Procedia 00 (2017) 000 – 000

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5. Conclusions This attempt addresses the prediction of High cycle fatigue behaviour of defective A356-T6 aluminium alloy. An engineering probabilistic approach was specially developed using Finite Element Methodology coupled with Monte Carlo Simulation. Particular focus was put on consideringthe effect of material dispersion due to the SDAS scattering. According to the findings, it can be concluded that: (i) HCF Response of A356-T6 alloy shows a large dispersion due to the random aspect of its microstructure(SDAS). The deterministic models seem to be unable for evaluating the remaining Al fatigue life, which confirms the need for an engineering approach that takes into account the SDAS dispersion. (ii) Using the developed approach for different defect sizes and different load amplitude, a good agreement was found between thesimulated results and experimental data for predicting A356-T6 fatigue life. (iii) The iso-Probabilistic a-N curves corresponding to 5%, 50% and 95% fatigue reliability loadings have been performed. This method allows engineers to be engaged in practical problems for predicting the fatigue life of A356-T6 structures in a more efficient and reliable way. (iv) The suggested approach exhibits good ability in improving the deterministic fatigue life prediction by considering the effect of microstructure (SDAS) dispersions. Mohamed IbenHouriya, Yves Nadot, RaoufFathallah, Matthew Roy. Daan M. Maijer. Influence of casting defect and SDAS on the multiaxial fatigue behaviour of A356-T6 alloy including mean stress effect. International Journal of Fatigue; 2015, 80: 90-102. M.J. Roy, Yves Nadot, C. Nadot-Martin, P.-G. Bardin, D.M. Maijer. Multiaxial Kitagawa analysis of A356-T6.International Journal of Fatigue; 2011,33:823-832. M. Roy, Yves Nadot, D.M. Maijer, G. Benoit. Multiaxial fatigue behaviour of A356-T6. Fatigue & Fracture of Engineering Materials & Structures; 2012, 35: 1148-1159. Y. Nadot, T. Billaudeau. Multiaxial fatigue limit criterion for defective materials. Engineering Fracture Mechanics; 2006, 73: 112-133. M. Vincent, C. Nadot-Martin, Y. Nadot, A. Dragon. Fatigue from defect under multiaxial loading: Defect Stress Gradient (DSG) approach using ellipsoidal Equivalent Inclusion Method. International journal of fatigue; 2014, 59: 176-187. Q.G. Wang, D. Apelian, D.A. Lados.Fatiguebehavior of A356-T6 aluminium cast alloys. Part II. Effect of microstructural constituents. Journal of Light Metal; 2001, 1:85-97. P. Li, P.D. Lee, D.M. Maijer, T.C. Lindley. Quantification of the interaction within defect populations on fatigue behavior in an aluminum alloy. ActaMaterialia; 2009, 57 3539-3548. References