Volume 28, Issue 4 (July 2000)
The Influence of Specimen Size on the Fracture Behavior of a Structural Steel at Different Temperatures
A broad experimental study was carried out in order to analyze the influence of different geometrical parameters (thickness, width, and crack length) and temperature on the fracture behavior of a structural steel. The J-integral versus crack growth resistance curves (J-R curves) were determined using indirect measurements of the crack size based on the variation of the specimen compliance, together with the physical determination of crack lengths obtained during testing using a color marking procedure. This last technique allows the reliability and accuracy of the data to be improved and provides additional information that can be used to reduce the typical scatter of the results. Only the initial crack size of the specimen has an influence on the J-R behavior of the steel due to the triaxiality modification of the crack tip stress state developed in the specimen. On the other hand, the J-R curve of the steel is also independent of temperature. Temperature affects only the J values at which cleavage or unstable fracture takes place.