Rationale

Annex A9 (section A9.6.5) provides users with a specific procedure/strategy aimed at establishing the coefficients, C1 and C2, of the power law regression line used to determine JQ/JIc. This procedure is meant to avoid inclusion of data points corresponding to apparent negative crack growth or other anomalies at the start of the test (see Note A9.1). The same procedure, however, is not mentioned in Annex A11, when covering the power law regression of (d, Da) data points for the establishment of dQ/dIc. Since there are no technical reasons that the same procedure should also be applicable to CTOD, it is proposed here to add it to Annex A11 (section A11.6.5 and new Note A11.1). Moreover, an obvious error in Eq. (A11.5) will be corrected. NOTE: there is currently a E08.07 ballot in progress to merge and consolidate the provisions of Annexes A8 and A9 (J-integral) and of Annexes A10 and A11 (CTOD, d). If both this and the present ballot are approved, the changes proposed here will be applied to the consolidated Annex A10 (A11 will be removed).