PSI - Issue 34

Camilla Ronchei et al. / Procedia Structural Integrity 34 (2021) 166–171 C. Ronchei, S. Vantadori, D. Scorza, A. Zanichelli, A. Carpinteri / Structural Integrity Procedia 00 (2021) 000 – 000

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Even if this paper represents a first attempt to apply the Carpinteri et al. criterion to AM metals, the obtained results in terms of number of loading cycles to failure are satisfactory, falling mostly into scatter band 3x and being the mean value of RMS T equal to about 2.5. Based on the above results, the Carpinteri et al. criterion seems to be capable of accurately estimating the fatigue life of AM metals. However, further investigations are needed in order to theoretically take into account the presence of both tensile residual stresses and high surface roughness.

4.0

1.0 MEAN SQUARE ERROR , T RMS TENSION 2.0 3.0

TORSION

BIAXIAL

0.0

LOADING CONDITION

Fig. 3 Mean square error value computed for AM Ti-6Al-4V specimens.

Acknowledgements The present research work is supported by Italian Ministry of University and Research (P.R.I.N. National Grant 2017, Project code 2017HFPKZY; University of Parma Research Unit). References Araújo, J.A., Dantas, A.P., Castro, F.C., Mamiya EN, Ferreira, J.L.A., 2011. On the characterization of the critical plane with a simple and fast alternative measure of the shear stress amplitude in multiaxial fatigue. International Journal of Fatigue 33, 1092 – 100. Carpinteri, A., Ronchei, C., Scorza, D., Vantadori, S., 2015. Fatigue life estimation for multiaxial low-cycle fatigue regime: the influence of the effective Poisson ratio value. Theoretical and Applied Fracture Mechanics 79, 77-83. Molaei, R., Fatemi, A., Phan, N., 2018. Significance of hot isostatic pressing (HIP) on multiaxial deformation and fatigue behaviors of additive manufactured Ti-6Al-4V including build orientation and surface roughness effects. International Journal of Fatigue 117, 352-70. Robinson, J.H., Ashton, I.R.T., Jones, E., Fox, P., Sutcliffe, C., 2019. The effect of hatch angle rotation on parts manufactured using selective laser melting. Rapid Prototyping Journal 25, 289-98. Solberg, K., Hovig, E.W., Sørby, K., Berto, F., 2021. Directional fatigue behaviour of maraging steel grade 300 produced by laser powder bed fusion. International Journal of Fatigue 149, 106229. Stern, F., Kleinhorst, J., Tenkamp, J., Walther, F., 2019. Investigation of the anisotropic cyclic damage behavior of selective laser melted AISI 316L stainless steel. Fatigue & Fracture of Engineering Materials & Structures 42, 2422-30. Tammas-Williams, S., Withers, P.J., Todd, I., Prangnell, P,B. 2016. The effectiveness of hot isostatic pressing for closing porosity in titanium parts manufactured by selective electron beam melting. Metallurgical and Materials Transactions A 47, 1939 – 46. Walat, K., Łagoda, T., 2014. Lifetime of semi -ductile materials through the critical plane approach. International Journal of Fatigue 67, 73 – 7. 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 – 14 Yadollahi, A., Mahmoudi, M., Elwany, A., Doude, H., Bian, L., Newman, J.C., 2020. Fatigue-life prediction of additively manufactured material: effects of heat treatment and build orientation. Fatigue Fatigue & Fracture of Engineering Materials & Structures 43, 831 – 44.