Issue 41

V. Shlyannikov et alii, Frattura ed Integrità Strutturale, 41 (2017) 31-39; DOI: 10.3221/IGF-ESIS.41.05 38 a) b) Figure 11 : Crack growth rate as a function of (a) elastic and (b) plastic SIFs for deepest point of the crack front. a) b) Figure 12 : Crack growth rate as a function of (a) elastic and (b) plastic SIFs for both alloys and different temperature conditions. C ONCLUSIONS atigue surface crack growth is studied through experiments and computations for aluminum alloys D16T and B95AT (analogue of 2024 and 7075 aluminum). For both alloys the increasing of test temperature leads to degradation of mechanical properties. By experimental studies for considered temperature conditions the relations between the crack sizes on the free surface of specimen, CMOD, crack growth rate and aspect ratio were obtained. For the same specimen configuration and the different crack front position the elastic and elastic-plastic constraint parameters were analyzed as a function of material properties and temperatures conditions. It is stated that the plastic SIF, which is sensitive to the constraint effects and elastic-plastic material properties, is attractive as the self-dependent unified parameter for characterization of the material fracture resistance properties. R EFERENCES [1] Shlyannikov, V.N., Tumanov, A.V., Characterization of crack tip stress fields in test specimens using mode mixity parameters, Int. J. Fract., 185 (2014) 49-76. [2] Shlyannikov, V.N., Zakharov, A.P., Multiaxial crack growth rate under variable T-stress, Eng. Fract. Mech., 123 (2014) 86–99. F