Rationale

Since its introduction, E1820 has required the resistance curve (single-specimen) procedure to be used for determining a J-R curve or a d-R curve, since the J-integral and d calculations according to the basic (multi specimen) method did not contain the crack growth correction. Currently, however, the basic procedure J and d calculations include accurate crack growth corrections, and reliable J-R and d-R curves can be evaluated using the relationships available in the standard. The revisions proposed in this ballot define the evaluation of resistance curves obtained from individual data points corresponding to multiple specimens evaluated using the basic test procedure. This revision was already balloted in 2019-2020, and received a few persuasive negatives. However, due to a change in the chairpersonship of the E08.07.05 task group and the occurrence of the COVID pandemic, the item was dropped. After addressing the negatives and making additional changes, this revision is now reproposed.