Rationale

A relatively popular and alternative method for measuring initial and final crack sizes from the fracture surfaces of fatigue and fracture specimens is the Area Average Method, which measures the surface area enclosed by the crack front, the specimen lateral surfaces (or the side-groove roots for side-grooved specimens), and a reference line corresponding to the origin of crack size measurements. This area is divided by the specimen thickness or net thickness to obtain the crack size. It is herein proposed to add the Area Average Method to E1820 as an alternative to (not as a replacement of) the existing 9 Point Average Method. This item has already been through four subcommittee ballot rounds, and has receive multiple persuasive negatives and comments. Negative votes and comments have been discussed in depth during the E08.07.05 task group meetings held in Denver (May 2023) and Washington DC (November 2023), as well as within several email exchanges between the Technical Contact and various task group members. The ballot item, as presented here, is the result of these discussions, and represents the most current version after all the modifications. All proposed changes with respect to the current version of E1820 are marked with “Track Changes”.