Application of CTOD in atomistic modeling of fracture

•Application of a CTOD crack flange extrapolation method.•Examination of flange method on new materials and crack geometries.•Accuracy for flange method in iron compared to silicon.•Dislocation activity suggested to account for differences between Si and Fe.

In this presentation we first review a method to use crack tip displacements and an estimate of the plastic zone to estimate fracture toughness. The same procedure was then applied on nanosized bcc-Fe cantilever beams with an initial crack. The results were then compared to literature. It was found that the fracture mechanical calculations should reflect the deformation processes at the crack tip in order to give accurate results. Further investigation is needed to determine whether the flange extension method can be used as a robust measure of fracture toughness.