Fracture toughness determination in the ductile-to-brittle transition regime pre-cracked Charpy specimens compared with standard compact specimens

摘要

More than 400 pre-cracked Charpy specimens have been tested in the ductile-to-brittle transition regime. Their fracture behaviour was compared with that of standardised C(T) specimens of the Euro Fracture Toughness Dataset. It was found that for a wide range of temperatures the type of the specimen less affects the lower bound toughness. Toughness data above the lower bound were found to be specimen size and geometry dependent. The differences in fracture toughness between standardised C(T) specimen and pre-cracked Charpy specimens can not be verified in the conventional way by using statistical weakest link size effect predictions and specimen size criteria as proposed in test standards.