CTOD – Crack Tip Opening Displacement


Assessment of material fracture toughness and resistance to Crack propogation


LMATS is now equipped with Crack Tip Opening Displacement or CTOD test method which is used to measure the resistance of a material to the propagation of a crack. CTOD is used on materials that can show some plastic deformation before failure occurs causing the tip to stretch open. Accurate measurement of this displacement is one of the essentials of the test.


Crack Tip Opening Displacement (or CTOD) has been he most widely used fracture toughness parameter within the oil and gas industry. CTOD is an ideal parameter for characterising the fracture toughness of medium strength carbon manganese steels used in pressure vessels, offshore platforms and pipelines where the application of linear elastic fracture mechanics was insufficient to account for their ductility.

Fracture toughness testing (CTOD testing) tested in accordance with BS 7448, ASTM E1290, ISO 12135 and ISO 15653.