Active Standard: E1921 - 13
Modifications to Sections 8.6.2, 8.6.3, 8.9.1, and 9.3 are proposed to address data quality assurance (QA). In Section 8.6.2, it is proposed to add a repeatability check for initial unloading/reloading sequence and require pretest compliance to be within 10% of average precrack length. The pretest compliance check was actually just moved from 8.6.3. Guidance for the value of E to use for the compliance expressions was also provided so that the requirement for accurately predicting the precrack length could be met. This guidance was copied directly from the new surface crack testing standard. Additionally, recommendations are provided for correcting the test setup if the accuracy and precision requirements are not met. Finally, the equation for Bn would be eliminated from this section. In Section 8.9.1, it is proposed to add a post-test requirement that the compliance to be within 5% of measured crack size using the same value of E used in 8.6.2, and in Section 9.3 there is a proposed modification to not allow data to be discarded unless the requirements in E1820, Section 9.1, and 8.9.1 are not met.
Draft Under Development