Simplified Method for Determination of Fracture Toughness in Transition Temperature Region

The fracture toughness KJC values of small specimens in the transition temperature region were analyzed to confirm the offset method standarized by JSPS 129 Committee. The offset method is a very useful method for the determination of lower-bound fracture toughness KJCi of material especially in the lower shelf temperature region where the stable crack growth is smaller than about 0.2mm. The KJCi values obtained from the offset method showed a good agreement with the KIC values of large specimens per ASTM E399 and the KJCi value from the fractography method standarized by JSPS 129 Committee.