Statistical treatment of fracture mechanics data and correlation with Charpy energy

Abstract Most steels are qualified by the transition temperature resulting from the impact test, i.e. T 27J can be taken out of tables from technical delivery codes. Both, expenses and effort of impact tests are much lower than fracture mechanics testing. Yet fracture mechanics toughness values allow a quantitative safety analysis of steel structures, whereas the Charpy values can only be used for an experienced based design. To combine both features it is useful to find a correlation between impact energy and a characteristic value from fracture mechanics testing, i.e. J-Integral. Because of the great scatter of the fracture toughness values in the brittle region of the transition curve, Wallin has developed the Mastercurve concept which served as a basis for an ASTM standard in 1998 [1] . With the help of the Mastercurve concept it is possible to describe the lower shelf region of the transition curve with the need of only six specimen. In case of steel structures a safety concept to avoid brittle fracture has been developed for Eurocode 3, Annex C [2] . By means of linking the Mastercurve concept to the T 27J temperature —the European design code—which is usually applied in steel design, it is possible to derive toughness requirements based on a fracture mechanics concept. The validation of the Mastercurve concept, a transition temperature correlation and the implementation of a safety concept according to Eurocode 3, Annex C, applied for different ship steel grades, are in focus of this work.