PSI - Issue 42

Teresa Morgado et al. / Procedia Structural Integrity 42 (2022) 1545–1551 Morgado et al./ Structural Integrity Procedia 00 (2019) 000 – 000

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5. Conclusions After comparing the results of the relative errors obtained in empirical life prediction models, it is concluded that: • the empirical model by Murakami et al. (1989) cannot be used for 6060 T4 alloy with hollow rectangular cross section extruded pieces and for 6060 T1 extruded alloys in solid rectangular cross-section extruded pieces. • the empirical model by Ueno et al. (2012) cannot be used for 6060 T4 alloy with hollow rectangular cross-section extruded pieces and for 6060 T1 alloy with solid rectangular pieces obtained by extrusion. • the empirical model by Schönbauer et al. (2016) cannot be used for the 6060 T1 alloy in solid rectangular cross section pieces obtained by extrusion. It is also concluded from this work that considering the same material, the fatigue life prediction models depend on the following parameters: stress ratio, hardness, intrinsic manufacturing defects, manufacturing process, heat treatment of the material and piece geometry. In addition, new models were developed to predict the fatigue limit stress for extruded pieces considering the defects area, hardness, and the stress ratio: equations (10) and (11) to 6060T4 aluminium hollow rectangular cross-section; and equations (12) and (13) to 6060T1 aluminium solid rectangular cross-section. Acknowledgements The authors acknowledge Fundação para a Ciência e a Tecnologia (FCT.IP) for its financial support through the grant UIDB/00667/2020 (UNIDEMI) and to ADLA – Aluminium Extrusion, S.A. for the extruded material supply. References ASTM E3-11 (2017), 2017. Standard Guide for Preparation of Metallographic Specimens. West Conshohocken, PA. ASTM E384 - 17, 2017. Standard Test Method for Microindentation Hardness of Materials, ASTM International. West Conshohocken, PA. ASTM E8/E8M - 21, 2021. Standard Test Methods for Tension Testing of Metallic Materials. West Conshohocken, PA. Han, F., Liu, Y., Liu, W., Cui, Z., 2017. Circular economy measures that boost the upgrade of an aluminum industrial park. J. Clean. Prod. 168, 1289 – 1296. Morgado, T., 2016. Failure of steel coupling used in railway transport. In: Makhlouf, A.S.H., Aliofkhazraei, M. (Eds.), Handbook of Materials Failure Analysis with Case Studies from the Aerospace and Automotive Industries. UK, pp. 449 – 469. Mori, A. De, Timelli, G., Berto, F., 2018. High Temperature Fatigue Behaviour of Secondary AlSi7Cu3Mg Alloys. In: Jesus, A. de, Correia, J.A., Neves, A.Ma., Calçada, R.A., Fernandes, A. (Eds.), Proceedings of the 19th International Colloquium on Mechanical Fatigue of Metals. Universidade do Porto - Faculdade de Engenharia, Porto, p. 29,30. Murakami, Y., Kawakami, K., Duckworth, W.E., 1991. Quantitative evaluation of effects of shape and size of artificially introduced alumina particles on the fatigue strength of 1.5NiCrMo (En24) steel. Int. J. Fatigue 13, 489 – 499. Murakami, Y., Kodama, S., Konuma, S., 1989. Quantitative evaluation of effects of non-metallic inclusions on fatigue strength of high strength steels. I: Basic fatigue mechanism and evaluation of correlation between the fatigue fracture stress and the size and location of non-metallic inclusions. Int. J. Fatigue 11, 291 – 298. Murakami, Y., Usuki, H., 1989. Quantitative evaluation of effects of non-metallic inclusions on fatigue strength of high strength steels. II: Fatigue limit evaluation based on statistics for extreme values of inclusion size. Int. J. Fatigue 11, 299 – 307. Schönbauer, B.M., Yanase, K., Endo, M., 2016. VHCF properties and fatigue limit prediction of precipitation hardened 17-4PH stainless steel. Int. J. Fatigue 88, 205 – 216. Tajiri, A., Nozaki, T., Uematsu, Y., Kakiuchi, T., Nakajima, M., Nakamura, Y., Tanaka, H., 2014. Fatigue Limit Prediction of Large Scale Cast Aluminum Alloy A356. Procedia Mater. Sci. 3, 924 – 929. Ueno, A., Nishida, A., Miyakawa, M., Yamada, S., Kikuchi, K., 2012. Fatigue Limit Estimation of Aluminium Die-Casting Alloy by Means of √area Method. Proc. 31st Symp. Fatigue (in Japanese) 159 – 163. Ueno, Akira, Nishida, M., Miyakawa, S., Yamada, K., Kikuchi, S., 2014. Fatigue limit estimation of aluminum die- casting alloy by means of √area method. Zair. Soc. Mater. Sci. Japan 63, 844 – 849.