Abstract
Structural strength may degrade during the service life of an aircraft due to undetected material defects or accidental damages. Additively manufactured or welded structures are particularly susceptible to fatigue cracking due to stress concentration at the surface and internal material defects. Despite significant benefits provided by the laser-based manufacturing techniques, there is still a lack of understanding how these parts fail under cyclic loading. This study aims to investigate the effect of internal material defects on the high cycle fatigue (HCF) behaviour of Ti-6Al-4V. It is shown that internal fish-eye fatigue fracture is a dominant failure mode if a subsequent surface treatment technique is applied. A probabilistic lifetime assessment framework for predicting the joint durability and its scatter in the HCF regime is developed. A good agreement between the modelling results and experiments is demonstrated.
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References
Cao, F., Chandran, K.: The role of crack origin size and early stage crack growth on HCF of powder metallurgy Ti-6Al-4V alloy. Int. J. Fatigue 102, 48–58 (2017)
Chapetti, M.: Fatigue propagation threshold of short cracks under constant amplitude loading. Int. J. Fatigue 25, 1319–1326 (2003)
El Haddad, M., Topper, T., Smith, K.: Prediction of non propagating cracks. Eng. Fract. Mech. 11(3), 573–584 (1979)
Fomin, F., Horstmann, M., Huber, N., Kashaev, N.: Probabilistic fatigue-life assessment model for laser-welded Ti-6Al-4V butt joints in the HCF regime. Int. J. Fatigue 116, 22–35 (2018a)
Fomin, F., Klusemann, B., Kashaev, N.: Surface modification methods for fatigue properties improvement of laser-beam-welded Ti-6Al-4V butt joints. Procedia Struct. Integrity 13, 273–278 (2018b)
Forman, R.G., Mettu, S.R.: Behavior of surface and corner cracks subjected to tensile and bending loads in Ti-6Al-4V alloy. ASTM STP 113, 519–546 (1992). ASTM, Philadelphia
Gong, H., Rafi, K., Gu, H., Janaki Ram, G.D., Starr, T., Stucker, B.: Influence of defects on mechanical properties of Ti-6Al-4V components produced by selective laser melting and electron beam melting. Mater. Des. 86, 545–554 (2015)
Kashaev, N., Ventzke, V., Horstmann, M., Chupakhin, S., Riekehr, S., Falck, R., Maawad, E., Staron, P., Schell, N., Huber, N.: Effects of laser shock peening on the microstructure and fatigue crack propagation behaviour of thin AA2024 specimens. Int. J. Fatigue 98, 223–233 (2017)
Kitagawa, H., Takahashi, S.: Applicability of fracture mechanics to very small cracks or the cracks in the early stage. In: Proceedings of the 2nd International Conference on Mechanical Behaviour of Materials, pp. 627–631, Boston, MA (1976)
Kuroshima, Y., Ikeda, T., Harada, M., Harada, S.: Subsurface crack growth behavior on HCF of high strength steel. Trans. Jpn. Soc. Aeronaut. and Space 64, 2536–2541 (1998)
Li, Y., Zhang, L., Fei, Y., Liu, X., Li, M.: On the formation mechanisms of fine granular area on the fracture surface for high strength steels in the VHCF regime. Int. J. Fatigue 82, 402–410 (2016)
Mardaras, J., Emile, P., Santgerma, A.: Airbus approach for F&DT stress justification of additive manufacturing parts. Procedia Struct. Integrity 7, 109–115 (2018)
McEvily, A., Velasquez, G.: Fatigue crack tip deformation processes as influenced by the environment. Metall. Trans. A 23, 2211–2221 (1992)
Murakami, Y.: Metal Fatigue: Effects of Small Defects and Nonmetallic Inclusions, 1st edn. Elsevier, Oxford (2002)
Newman, J.: A crack opening stress equation for fatigue crack growth. Int. J. Fatigue 24, 131–135 (1984)
Oguma, H., Nakamura, T.: Fatigue crack propagation properties of Ti-6Al-4V in vacuum environments. Int. J. Fatigue 50, 89–93 (2013)
Polak, J.: Cyclic deformation, crack initiation, and low-cycle fatigue. In: Ritchie, R., Murakami, Y. (eds.) Comprehensive Structural Integrity: Cyclic Loading and Fracture, pp. 1–39. Elsevier Pergamon, Boston (2003)
Ritchie, R., Davidson, D., Boyce, B., Campbell, J., Roder, O.: High cycle fatigue of Ti-6Al-4V. Fatigue Fract. Eng. M. 22, 621–631 (1999)
Tanaka, K., Akiniwa, Y.: Resistance curve method for predicting propagation threshold of the short fatigue cracks at notches. Eng. Fract. Mech. 30(6), 863–876 (1988)
Yoshinaka, F., Nakamura, T., Takaku, K.: Effects of vacuum environment on small fatigue crack propagation in Ti-6Al-4V. Int. J. Fatigue 91, 29–38 (2016)
Zerbst, U., Vormwald, M., Pippan, R., Gaenser, H., Sarrazin-Baudoux, C., Madia, M.: About the fatigue crack propagation threshold of metals as a design criterion - a review. Eng. Fract. Mech. 153, 190–243 (2016)
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Fomin, F., Kashaev, N. (2020). Probabilistic Reliability Assessment of a Component in the Presence of Internal Defects. In: Niepokolczycki, A., Komorowski, J. (eds) ICAF 2019 – Structural Integrity in the Age of Additive Manufacturing. ICAF 2019. Lecture Notes in Mechanical Engineering. Springer, Cham. https://doi.org/10.1007/978-3-030-21503-3_39
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DOI: https://doi.org/10.1007/978-3-030-21503-3_39
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