Molecular statics simulation of fracture in -iron

The behaviour of mode I cracks in -Fe is investigated using molecular statics computer simulation methods with an EAM potential. A double-ended crack of finite size embedded in a cylindrical simulation cell and fixed boundary conditions are prescribed along the periphery of the cell, whereas periodic boundary conditions are imposed parallel to the crack front. The displacement field of the finite crack is represented by that of an equivalent pile-up of opening dislocations distributed in a manner consistent with the anisotropy of the crystal and traction-free conditions of the crack faces. The crack lies on the plane and the crack front is located along , or directions. The crack tip response is rationalized in terms of the surface energy of the cleavage plane and the unstable stacking energies of the slip planes emanating from the crack front.