PSI - Issue 34

Harry O. Psihoyos et al. / Procedia Structural Integrity 34 (2021) 253–258 Harry O.Psihoyos et al. / Structural Integrity Procedia 00 (2021) 000 – 000

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5. Conclusions In the present work, a modelling framework for the estimation of fatigue life of SLM Ti-6Al-4V was developed. The framework consists of two parts: the prediction of defects or susceptible areas for defect formation and defect based fatigue life estimation. Sma ll fatigue crack growth properties of AM Ti-6Al-4V were a lso considered. The prediction results were compared with ava ilable experimenta l litera ture data to verify the models. It was considered that the fatigue fa ilure is governed by only one defect. After the melt pool-based defect characterization of the specimen, it was considered that the most critica l defect lied on the surface of the sma llest cross section. The fatigue life prediction model based on the proper selection of SIF or K-solution. Although, the initia l estimation of fatigue life was correlated with experimenta l data quite well, for the lower levels of applied stresses the crack did not grow ma inly because of the choice of initia l defect size. Future studies will be required to further investigate the effect of defect size on theprediction results as well as the considerationof multiple crackgrowth. References Cunningham, R., Zhao, C., Parab, N., Kantzos, C., Pauza, J., Fezzaa, K., Sun, T., Rollett, A.D., 2019. Keyhole threshold and morphology in laser melting revealed by ultrahigh-speed X-ray imaging. Science 363, 849 – 852. Du, L., Qian, G., Zheng, L., Hong, Y., 2021. Influence of processing parameters of selective laser melting on high -cycle and very-high-cycle fatigue behaviour of Ti-6Al-4V. Fatigue & Fracture of Engineering Materials & Structures 44, 240 – 256. Forman, R., Shivakumar, V., 1986. Growth Behavior of Surface Cracks in the Circumferential Plane of Solid and Hollow Cylinders. ASTM Spec. Tech. Publ. 59 – 74. Gong, H., Rafi, K., Gu, H., Janaki Ram, G.D., Starr, T., Stucker, B., 2015. Influence of defects on mechanical properties of Ti-6Al-4V components produced by selective laser melting and electron beam melting. Materials & Design 86, 545 – 554. Hu, Y.N., Wu, S.C., Withers, P.J., Zhang, J., Bao, H.Y.X., Fu, Y.N., Kang, G.Z., 2020. The effect of manufacturing defects on the fatigue life of selective laser melted Ti-6Al-4V structures. Materials & Design 192, 108708. Jiménez, M., Romero, L., Domínguez, I.A., Espinosa, M.D.M., Domínguez, M., 2019. AdditiveManufacturing Technologies: An Overview about 3D Printing Methods and Future Prospects. Complexity 2019. Sanaei, N., Fatemi, A., 2021. Defect-based fatigue life prediction of L-PBF additive manufactured metals. Engineering Fracture Mechanics 244, 107541. Sanaei, N., Fatemi, A., 2020. Defects in Additive Manufactured Metals and Their Effect on Fatigue Performance: A State-of-the-Art Review. Progress in Material Science 117, 100724. Snow, Z., Nassar, A.R., Reutzel, E.W., 2020. Invited ReviewArticle: Review of the formation and impact of flaws in powder bed fusion additive manufacturing. Additive Manufacturing 36, 101457. Tang, M., Pistorius, P.C., Beuth, J.L., 2017. Prediction of lack-of-fusion porosity for powder bed fusion. AdditiveManufacturing 14, 39 – 48. Yadollahi, A., Mahmoudi, M., Elwany, A., Doude, H., Bian, L., Newman, J.C., 2020. Fatigue‐life prediction of additively man ufactured material: Effects of heat treatment and build orientation. Fatigue & Fracture of Engineering Materials & Structures 43, 831 – 844. Yadollahi, A., Mahtabi, M.J., Khalili, A., Doude, H.R., Newman, J.C., 2018. Fatigue life prediction of additively manufactured material: Effects of surface roughness, defect size, and shape. Fatigue & Fracture of Engineering Materials & Structures 41, 1602 – 1614. Yadollahi, A., Shamsaei, N., 2017. Additive manufacturing of fatigue resistant materials: Challenges and opportunities. Int ernational Journal of Fatigue 98, 14 – 31. Zhai, Y., Lados, D.A., Brown, E.J., Vigilante, G.N., 2016. Fatigue crack growth behavior and microstructural mechanisms in Ti -6Al-4V manufactured by laser engineered net shaping. International Journal of Fatigue 93, 51 – 63.