Determining ductile fracture toughness in metals

Ductile fracture toughness determination, such as the f-integral vs. crack growth resistance (J-R) curve, is a useful tool for evaluating a material's structural integrity in the presence of preexisting defects. The J-R curve can calculate the work per unit of fracture surface area needed to drive crack growth. Three widely used J-R curve test methods in metals are elastic unloading compliance (EUC), normalization, and direct current potential drop (DCPD). The main differences between these methods involve crack size determination and different types of specimens can be used for each J-R curve test. The EUC method has gained wide popularity for the J-R curve test after its introduction. A technique has been developed by a team of researchers to address the challenges faced by the EUC method.