PSI - Issue 2_B

V. Shlyannikov et al. / Procedia Structural Integrity 2 (2016) 3248–3255 Author name / Structural Integrity Procedia 00 (2016) 000–000

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4. Conclusions Fatigue surface crack propagation in cruciform specimens from D16T aluminum alloy under biaxial loading was studied. Experimental results showed that biaxial in-plane loading led to two main stages of cyclic fracture process of surface crack. A significant reduction of the crack growth rate was observed in the direction of the deepest point of the crack front with respect to the crack front intersection with the free surface of the tested specimens as a function of loading conditions. The experimental and numerical results of the present study background provide an opportunity to explore the suggestion that crack growth rate may be represented by the plastic stress intensity factor, rather than the magnitude of the elastic SIF alone. The fatigue fracture diagram in terms of plastic SIF was introduced as a generalized diagram in normalized coordinates. The generalization of typical fatigue fracture diagrams in normalized coordinates provides a single curve that describes the strong correlation between crack growth rate dc/dN and plastic SIF Kp for different loading conditions. References Shlyannikov, V.N., Kislova S.Yu., Tumanov, A.V., 2010. Inclined semi-elliptical crack for predicting crack growth direction based on apparent stress intensity factors, Theoret. Appl. Fract. Mech. 53, 185-193. Shlyannikov, V.N., Tumanov, A.V., 2011. An inclined surface crack subject to biaxial loading, Int. J. Solids Struct. 48, 1778-1790. Shlyannikov, V.N., Tumanov, A.V., Zakharov A.P., 2016. Surface crack growth subject to bending and biaxial tension-compression, Frattura ed Integrita Strutturale 35, 257-267. Shlyannikov, V.N., Tumanov, A.V., 2014. Characterization of crack tip stress fields in test specimens using mode mixity parameters, Int. J. Fract. 185, 49-76. Yarema S. Ya. Panasiuk. V.V., 1996. General features of fatigue fracture diagrams of metals, Strength problems 1, 30-35.