Fracture # 1995 Edinburgh
A review of the Fracture Mechanics methodology for characterising toughness is given. It is shown that the fracture resistance R is derived by computing an energy difference. It is noted that R is dependent on the constraint in the crack tip region and that this leads to the very complex behaviour observed in Charpy tests. The different types of fracture observed in this test are then discussed and the consequences for pipe performance described. It is concluded that the high toughness occurring under plane stress conditions is critical in determining performance.