Issue 49

S.A.G. Pereira et alii, Frattura ed Integrità Strutturale, 49(2019) 412-428; DOI: 10.3221/IGF-ESIS.49.40 418 Fig. 6 a) illustrates the negative consequences of an inadequate choice of points for extrapolating the T value. Calculation of T stress considering elements at unreasonable short distances from the end of the crack, including the extremity itself ( x/a=0 ), culminates in values that are unrealistic. This is shown in Fig. 6, and is also discussed in [17]. a) / 0 x a  b) / 0.0125 x a   c) / 0.025 x a   d) / 0.0375 x a   e) / 0.05 x a   Figure 6 : Variation of normalized T value for β= 60°, Stress Method. Fig. 8 a) presents the specimen to obtain the value of K Ic according to the ASTM E399 standard. Fig. 8 b) presents a specimen with a slight difference from the previous one, for which an independent calibration using Abaqus software was performed.