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T Varga, F. Loibnegger:
"Low Striking Velocity Testing of Precracked Charpy-type Specimens";
Vortrag: ASTM Symposium, Seattle, Washington; 19.05.1999 - 20.05.1999; in: "PENDULUM IMPACT TESTING: A century of progress ", ASTM, STP 1380 (2000), ISBN: 0-8031-2864-9; S. 267 - 285.

The usual loading rate for impact testing is near 5 m/s. As it will be demonstrated, force-deflection-diagrams show strong oscillations, at least at the beginning. Investigations on realistic loading rates showed, however, in most practical cases effective loading rates below 0.1 m/s. Because this is true in nearly every case, a loading rate of 0.1 m/s sems to be sufficient for precracked specimens. If the loading rate is reduced from about 5 m/s to 0.1 m/s, the force-deflection-diagram can be evaluated without parasitic oscillations. Therefore measurements of fracture toughness, KId, Jd and the calculations of CTOD become easier. Regarding fracture work and specific fracture work, the steel investigated shows no significand difference if 5 m/s and 0.1 m/s impact velocity is compared. Fracture toughness characteristics will become comparable when transition temperature shifts below 20°C are negligible. If a transition shift above 15°C is of importance, the experimental results have to be treated differently. a substitution will become not practicable without a function converting the 0.1 m/s results to 5 m/s results and vice versa. If the steels tested are sufficiantly brittle, an extrapolation to the fracture toughness of larger sections will become possible