Research scientist, Fraunhofer-Institut für Werkstoffmechanik (IWM), Freiburg,
Research scientist, Swiss Federal Lab. for Materials Testing and Research (EMPA), Dübendorf,
Pages: 10 Published: Jan 2000
Based on a previous round-robin exercise of the German DVM task group on “Instrumented Impact Testing” with about 400 instrumented Charpy-specimens being tested, another exercise was performed to explore the possibilities of extended evaluations such as single-specimen methods. The previously determined multi-specimen cleavage JR-curve serves as a reference. Different methods — e.g., the key-curve method — were applied. Overall, the results are encouraging and the agreement of the calculated JR-curve with reference data is quite good especially for large amounts of crack extension. There was some uncertainty left in the first part of the JR-curve, where notch blunting and initiation of crack growth take place, and where the calculated curves tend to overestimate the crack resistance. Results of a new “blind” round-robin indicate improved results in this initial part of the JR-curve.
Charpy test, impact, instrumented impact testing, fracture toughness, crack resistance curve, single-specimen method, key-curve method, dynamic material behavior
Paper ID: STP14404S