PSI - Issue 13

8

Gustavo Henrique Bolognesi Donato et al. / Procedia Structural Integrity 13 (2018) 1879–1887 Leonardo G. F. Andrade and Gustavo H. B. Donato / Structural Integrity Procedia 00 (2018) 000–000

1886

Figure 6 presents the effects of varying thicknesses and W/B ratios. In this case, only r = 2 and deviation of 10% when compared to MBL model are presented. Here, it is worth noting the remarkable effect of thickness on stress triaxiality and thus M values. In most cases, the thicker is the specimen (e.g.: W = B ), the lower will be M value and the higher will be the validity limit of J-integral (see the case of C(T) specimen for example). The same trend happens for SE(B) and SE(T) specimens containing deep cracks, but an opposite phenomenon was identified for veru shallow cracks. In general, the presented results regarding a wide variety of M values represent a robust set of criteria for determining the validity limits of J -integral, thus allowing the validation of fracture toughness data obtained from laboratory testing of C(T), SE(B) and SE(T) testing.

Fig. 6. Influence of a/W on M values for varying geometries. 3D models with and n = 10 and W/B = 1, 2 and 4..