Issue 60

A. Elakhras et alii, Frattura ed Integrità Strutturale, 60 (2022) 73-88; DOI: 10.3221/IGF-ESIS.60.06

The values of G f and K IC were estimated for the four specimens representing each case of L/d individually by substituting the incremental increase steps value of C f in Eqn. (2,3). The CTOD at each incremental step of C f is obtained from Eqns. (4,5). Then, K IC -CTOD curves for specimens with L/d ratios equal 4, 5, 6, and their average curves can be drawn as shown in Figs. 6, 7, 8(a), for each case individually. By estimating the standard deviation (S.D) for the average values of CTOD at each incremental step, the average CTOD with minimum standard deviation is considered as a material parameter (CTODc S ), as shown in Fig. 6, 7, 8(b). The second fracture parameter, K IC S , was calculated by substituting CTODc S into K IC –CTOD's average curve, see Figs. 6, 7, 8(a). In addition, the effective crack length, C f S , proposed by ETPFM relationship at different notch lengths can be obtained from Eqn. (6).

a)K IC -CTODc curves

b)Relationship between S.D. and CTODc

Figure 6: MC-FD FRC at first cracking at different L/d ratios equals 4, 5 and 6.

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