Structural integrity assessment aspects of the Master Curve methodology

The Master Curve (MC) methodology, introduced more than two decades ago, has evolved, from only being a brittle fracture testing and analysis procedure, to a technological tool capable of addressing many more structural integrity issues like constraint and parameter transferability. The MC enables a complete characterization of a material’s brittle fracture toughness based on only a few small size specimens. The MC method has been shown to be applicable for practically all steels with a body-centered cubic lattice structure, generally identified as ferritic steels. The method combines a theoretical description of the scatter, a statistical size effect and an empirically found temperature dependence of fracture toughness. The fracture toughness in the brittle fracture regime is thus described with only one parameter, the transition temperature T₀. The basic MC method has been standardized in the ASTM standard E1921, the first standard that accounts for the statistical specimen size effect and variability in brittle fracture toughness. In this presentation some of the more resent advances of the MC technology are highlighted, with special emphasis on problems related to the use of the Master Curve in structural integrity assessment.