PSI - Issue 42

Rita Dantas et al. / Procedia Structural Integrity 42 (2022) 1676–1683 Rita Dantas / Structural Integrity Procedia 00 (2019) 000–000

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5. Conclusions

Within the scope of this work, ultrasonic fatigue tests were performed considering smooth specimens of S690 steel, in order to analyse the VHCF region. Therefore, an analytical approach was applied to design smooth specimens to resonate at a longitudinal natural frequency of 20 kHz and then to be tested in an ultrasonic machine. Thus, experimen tal data for the VHCF region was obtained and a mean curve, which was verified to be almost a horizontal asymptote, was determined. As future work, the frequency e ff ect will be quantified and analysed in more detail by performing experimental tests at lower frequencies, with the aim of establishing a model which can consider this e ff ect. Furthermore, it is intended to test notch specimens to study the notch sensitivity of this steel in the VHCF region. The authors would like to express their acknowledgements to FCT - Foundation for Science and Technology, which supported this work through the project PTDC / EME-EME / 7678 / 2020, Giga-Cycle Fatigue Behaviour of Engineering Metallic Alloys.This work (reference SFRH / BD / 151377 / 2021) is also co-financed by the Social European Fund – through the Northern Regional Operational Program (NORTE 2020), the Regional Operational Program of the Center (Centro 2020) and the Regional Operational Program of Alentejo (Alentejo 2020)- and by the Portuguese Foundation for Science and Technology – FCT under MIT Portugal. Additionally, the authors extend their gratitude to the project AARM 4.0 - Ac¸os de Alta Resisteˆncia na Metalomecaˆnica 4.0, with the reference POCI-01-0247-FEDER068492, co-financed by the European Regional Development Fund (ERDF), through the Operational Programme for Com petitiveness and Internationalization (COMPETE 2020), under the PORTUGAL 2020 Partnership Agreement. This work is also financially supported by national funds through the FCT / MCTES (PIDDAC), under the project MIT EXPL / SOE / 0054 / 2021 of MIT Portugal Program. Anes, V., Montalva˜o, D., Ribeiro, A., Freitas, M., Fonte, M., 2011. Design and Instrumentation of an Ultrasonic Fatigue Testing, in: Proceedings of the VHCF5—5th International Conference on Very High Cycle Fatigue, pp. 28–30. Bathias, C., Paris, P.C., 2004. Gigacycle Fatigue in Mechanical Practice. Marcek Dekker. doi: 10.1201/9780203020609 . Berger, G., Pyttel, B., Schwerdt, D., 2008. Beyond HCF - Is there a fatigue limit? Materialwissenschaft und Werksto ff technik 39, 769–776. doi: 10.1002/mawe.200800342 . Costa, P., Nwawe, R., Soares, H., Reis, L., Freitas, M., Chen, Y., Montalva˜o, D., 2020. Review of multiaxial testing for very high cycle fatigue: From ’Conventional’ to ultrasonic machines. Machines 8. doi: 10.3390/MACHINES8020025 . Furuya, Y., Matsuoka, S., Abe, T., Yamaguchi, K., 2002. Gigacycle fatigue properties for high-strength low-alloy steel at 100 Hz, 600 Hz, and 20 kHz. Scripta Materialia 46, 157–162. doi: 10.1016/S1359-6462(01)01213-1 . Furuya, Y., Torizuka, S., Takeuchi, E., Bacher-Ho¨chst, M., Kuntz, M., 2012. Ultrasonic fatigue testing on notched and smooth specimens of ultrafine-grained steel. Materials and Design 37, 515–520. doi: 10.1016/j.matdes.2012.01.035 . Ilie, P., Lesperance, X., Ince, A., 2020. Development of an ultrasonic fatigue testing system for gigacycle fatigue. Material Design and Processing Communications 2, 1–9. doi: 10.1002/mdp2.120 . Mora, R.P., 2010. Study of the fatigue strength in the gigacycle regime of metallic alloys used in aeronautics and o ff -shore industries. Ph.D. thesis. Arts et Me´tiers ParisTech. Murakami, Y., 2002. Metal fatigue: E ff ects of Small de ff ects and Nonmetallic Inclusions. 82. first ed., Ekevier Science. Nishijima, S., Kanazawa, K., 1999. Stepwise S-N curve and fish-eye failure in gigacycle fatigue. Fatigue and Fracture of Engineering Materials and Structures 22, 601–607. doi: 10.1046/j.1460-2695.1999.00206.x . Palin-Luc, T., Jeddi, D., 2018. The gigacycle fatigue strength of steels: A review of structural and operating factors, in: Procedia Structural Integrity, Elsevier B.V.. pp. 1545–1553. URL: https://doi.org/10.1016/j.prostr.2018.12.316 , doi: 10.1016/j.prostr.2018.12.316 . Sharma, A., Oh, M.C., Ahn, B., 2020. Recent advances in very high cycle fatigue behavior of metals and alloys—a review. Metals 10, 1–23. doi: 10.3390/met10091200 . Zimmermann, M., 2018. Very High Cycle Fatigue, in: Handbook of Mechanics of Materials. Springer Nature Singapore Pte, pp. 1–38. doi: 10. 1007/978-981-10-6855-3_43-1 . Acknowledgements References