Senior engineer, Westinghouse Research and Development Laboratory, Pittsburgh, Pa.
A round robin test program on the determination of JIc values of ductile materials was conducted by twelve different laboratories, representing five countries. The testing program was conducted under the auspices of the Elastic-Plastic Fracture subcommittee, E24.08, of ASTM Committee E24 on Fracture Testing of Materials. Each laboratory tested one blunt notched and five precracked compact specimens. The results showed very little scatter on JIc values when valid tests are performed. Both single specimen tests and multispecimen tests show excellent agreement.
Side grooved specimens were also tested to determine what possible differences exist between side grooved specimens and specimens not side grooved specimens. While the slope of the crack growth resistance (R) lines were different for the two geometries, the JIc values were essentially the same.
Paper ID: JTE10613J