This item is a second reballot of revisions to Annex A11 originally proposed in Ballot E08(14-01). The first reballot E08(14-03) addressed concerns expressed by a persuasive negative vote on E08(14-01). For the case of unstable crack extension during the test, it added a requirement that at least one data point of the minimum of four data points must lie between the 0.2 mm and 0.5 mm offset lines when determining Q. Under the original proposal, it was permissible to have all four data points lie between the 0.15 and 0.2 mm offset lines and the power law fit could be extrapolated to the intersection with the 0.2mm offset line. This is no longer the case. This latest ballot addresses a persuasive negative vote on E08(14-03). The prior revision inadvertently eliminated the data spacing requirement for the normal case of a stable test. The proposed changes discussed in the rationale have been now incorporated into new sections, A11.7 and A11.8, that appear after the qualification requirements for stable tests. The changes in this revision were presented at the E08.07.05 Task Group meeting in November 2014 and approved for reballot.
Keywordscrack initiation; crack-tip opening displacement; CTOD; ductile fracture; elastic-plastic fracture toughness; fracture instability; J-integral; J
Draft Under Development