Round-robin exercise on instrumented impact testing of precracked Charpy specimens (IAEA coordinated research program Phase 8)

Within topic area 2 (Loading Rate Effects) of the IAEA Coordinated Research Project Phase 8 (CRP-8), a round-robin exercise (RRE) was performed. This was aimed at measuring impact fracture toughness in the ductile-to-brittle transition region using precracked Charpy specimens of the JRQ steel tested on instrumented pendulum machines. The objective of the round-robin was twofold: 1) assessing the applicability of the Master Curve approach (ASTM E1921-05) to data obtained at impact loading rates of the order of 105 MPaVm/s; 2) validating a draft test procedure developed by sub-committee TC5 of the European Structural Integrity Society (ESIS), in the absence of an official testing standard (ISO or ASTM). A comprehensive analysis of the RRE results received to date will be presented in this paper, including an assessment of the overall data scatter and the lab-to-lab variability. In this context, an outlier data set has been identified and investigated in great detail. Based on the results presented, it is noted that the test procedure appears reliable and easy to follow for the various participants.