PSI - Issue 66

Andrea Zanichelli et al. / Procedia Structural Integrity 66 (2024) 471–477 Author name / Structural Integrity Procedia 00 (2025) 000–000

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Fig. 3. Calculated vs experimental fatigue life for each test examined by considering: (a) a smaller friction coefficient, and (b) a smaller and (c) a bigger value of the average material grain size. On the other hand, it could be interesting to examine the influence of the coefficient of friction and of the grain size on both fatigue life and crack orientation. Further, the effect of the average material grain size on the fatigue life is shown in Figures 3 (b) and (c), in which a value half and double the real one is considered, respectively. It can be observed that the fatigue life decreases by decreasing the value of the grain size, whereas the fatigue life increases as the grain size increases. A similar, although less pronounced, trend is observed for the crack orientation, which decreases for the smallest grain size and increases for the biggest one, of about 2°. 5. Conclusions In the present paper, experimental tests, available in the literature, carried out on an aluminium-copper alloy in partial slip regime with cylindrical contact, have been simulated by means of an analytical methodology proposed by the present authors. In particular, both the crack nucleation orientation and the fatigue life have been computed, and satisfactory results have been obtained in terms of fatigue life estimation, with a T RMS equal to 1.66, and crack nucleation location, whereas the computed crack orientation underestimates the real one. Then, it has been observed that the input parameters related to the contact geometry, the fretting loading and the material significantly affect the fatigue life, whereas they have a marginal effect on the crack nucleation orientation. References Almeida, G.M.J., Pessoa, G.C.V., Cardoso, R.A., Castro, F.C., Araújo, J.A., 2020. Investigation of crack initiation path in AA7050-T7451 under fretting conditions. Tribology International 144, 106103. Araújo, J.A., Almeida, G.M.J., Ferreira, J.L.A., da Silva, C.R.M., Castro, FC., 2017. Early cracking orientation under high stress gradients: The fretting case. International Journal of Fatigue 100: 611-618. Araújo, J.A., Nowell, D., Vivacqua, R.C., 2004. The use of multiaxial fatigue models to predict fretting fatigue life of components subjected to different contact stress fields. Fatigue and Fracture of Engineering Materials and Structures 27, 10, 967-978. Carpinteri, A., Ronchei, C., Scorza, D., Vantadori, S., 2015. Critical plane orientation influence on multiaxial high-cycle fatigue assessment. Physical Mesomechanics 18, 4, 348-354. Carpinteri, A., Boaretto, J., Fortese, G., Giordani, F., Rodrigues, R.I., Iturrioz, I., Ronchei, C., Scorza, D., Vantadori, S., Zanichelli, A., 2018. Welded joints under multiaxial non-proportional loading. Theoretical and Applied Fracture Mechanics 93, 202-210. Erena, D., Vázquez, J., Navarro, C., Talemi, R., 2020. Numerical study on the influence of artificial internal stress relief groove on fretting fatigue in a shrink-fitted assembly. Tribology International 151, 106443. Hertz, H., 1896. Miscellaneous Paper by Heinrich Hertz. New York: Macmillan & Co. Nowell, D., Hills, D.A., 1987. Mechanics of fretting fatigue tests. International Journal of Mechanical Sciences 29, 5, 355-365. Vantadori, S., Zanichelli, A., Araújo, J.A., 2020. Fretting fatigue of 7050-T7451 Al alloy: the influence of bulk mean stress. International Journal of Fatigue 140, 105816.