Use of Alternating Current Potential Drop for Determining J-Crack Growth Resistance Curves

摘要

The use of the ac potential drop technique as a single specimen method for J-R curve determination has been investigated. The technique involves passing an alternating current through the specimen and relating the changes in the potential drop across the crack mouth to changes in crack length occurring during the test. Two approaches for analyzing the measured potential drop signals have been evaluated, one of which enables accurate J-R curves to be determined. In addition, the ac potential drop technique has been compared to the corresponding dc potential drop technique. In general both techniques can yield accurate J-R curves.