Experience with ductile crack growth measurements applying the DC-PD technique to compact tension fracture specimens

In this paper is presented the experience obtained at Risoe in applying the direct current potential difference (DC-PD) technique to the indication of ductile crack initiation as well as to the quantitative measurement of the ductile tearing itself. The technique is used in connection with single specimen Jsub(R)-curve tests, employing compact tension (CT) specimens which may or may not contain side-grooves. The technique is based on the establishment of reference-curves, relating the change in electrical potential to the increase in ductile crack length in the CT-specimen