The Influence of the Out-of-Plane Constraint on Fracture Toughness of High Strength Steel at Low Temperatures

Abstract

The values of JIC measured in laboratories, when used in practical applications, may lead to conservative results in assessing the critical state of a structural element. When the thickness of the structural element is less than required by standards the fracture toughness can be much higher than measured in the laboratory. In this paper the fracture toughness of brittle or semi-brittle materials is discussed. The out-of-plane constraint is characterized in this paper by other quantity then the specimen thickness. This quantity can be related to the thickness if the thickness is uniquely defined.