Issue 41

A. Carpinteri et alii, Frattura ed Integrità Strutturale, 41 (2017) 66-70; DOI: 10.3221/IGF-ESIS.41.10 70 C ONCLUSIONS n the present paper, the multiaxial fatigue life assessment of notched structural components has been performed by employing a strain-based multiaxial fatigue criterion in conjunction with the concept of control volume, related to the SED approach proposed by Lazzarin and co-workers. In particular, the above assessment is carried out at a verification point, which is located at a certain distance from the notch tip, depending such a distance on both the biaxiality ratio and the control volume radii under Mode I and Mode III. Some uniaxial and multiaxial fatigue data, recently published in the literature, have been analysed to evaluate the effectiveness of the present criterion. The agreement between experimental and theoretical fatigue lives is quite satisfactory. In conclusion, the present criterion appears to be a promising tool to estimate fatigue lifetime of notched structures, although further investigations are needed by performing experimental tests characterised by fatigue ratio values different from  1 and different notch geometries. R EFERENCES [1] Susmel, L., Taylor, D., A novel formulation of the theory of critical distances to estimate lifetime of notched components in the medium-cycle fatigue regime, Fatigue Fract. Engng. Mater. Struct., 30 (2007) 567-581. DOI: 10.1111/j.1460-2695.2007.01122.x. [2] Neuber, H., Theory of Notch Stresses: Principles for Exact Calculation of Strength with Reference to Structural Form and Material, second ed., Springer Verlag, Berlin, (1958). [3] Nieslony, A., Sonsino, C.M., Comparison of some selected multiaxial fatigue assessment criteria, L.B.F. Report, No. FB-234 (2008). [4] Fatemi, A., Shamsaei, N., Multiaxial fatigue: an overview and some approximation models for life estimation, Int. J. Fatigue, 33 (2011) 948–958. DOI: 10.1016/j.ijfatigue.2011.01.003. [5] Carpinteri, A., Berto, F., Campagnolo, A., Fortese, G., Ronchei, C., Scorza, D., Vantadori, S., Fatigue assessment of notched specimens by means of a critical plane-based criterion and energy concepts, Theor. Appl. Fract. Mech., 84 (2016) 57-63. DOI: 10.1016/j.tafmec.2016.03.003. [6] Carpinteri, A., Ronchei, C., Spagnoli, A., Vantadori, S., Lifetime estimation in the low/medium-cycle regime using the Carpinteri–Spagnoli multiaxial fatigue criterion, Theor. Appl. Fract. Mech., 73 (2014) 120–127. DOI: 10.1016/j.tafmec.2014.06.002. [7] Carpinteri, A., Ronchei, C., Scorza, D., Vantadori, S., Fatigue life estimation for multiaxial low-cycle fatigue regime: the influence of the effective Poisson ratio value, Theor. Appl. Fract. Mech., 79 (2015) 77–83. DOI: 10.1016/j.tafmec.2015.06.013. [8] Berto, F., Lazzarin, P., Yates, J.R., Multiaxial fatigue of V-notched steel specimens: a non-conventional application of the local energy method, Fatigue Fract. Eng. Mater. Struct., 34 (2011) 921–943. DOI: 10.1111/j.1460- 2695.2011.01585.x. [9] Berto, F., Lazzarin, P., Tovo, R., Multiaxial fatigue strength of severely notched cast iron specimens, Int. J. Fatigue, 67 (2014) 15–27. DOI: 10.1016/j.ijfatigue.2014.01.013. [10] Berto, F., Campagnolo, A., Welo, T., Local strain energy density to assess the multiaxial fatigue strength of titanium alloys, Frattura ed Integrità Strutturale, 10 (2016) 69-79. DOI: 10.3221/IGF-ESIS.37.10. [11] Basan, R., Franulovic, M., Prebil, I., Crnjaric-Žic, N., Analysis of strain-life fatigue parameters and behaviour of different groups of metallic materials, Int. J. Fatigue, 33 (2011) 484–491. DOI: 10.1016/j.ijfatigue.2010.10.005. I