1 Terminology a b c a) Incubation – A process that leads to the event of crack nucleation. b) Nucleation – The event defined by the first appearance of new surface area. c) Microstructurally small cracking (MSC) – The processes and events dominated by the microstructure.

2 Where do we stand now ? We can: 1)simulate incubated cracks and planar crack nucleation/MSC from particle to grain. We can’t yet: 1)insert interface elements † and still do crack growth simulation in F3DNG or; 2)simulate post-incubation growth. i.e. will a crack nucleate, continue along the interface or both?

3 1% strain Fixed Displacement BC Interface elements F3DNG and Fracture Simulation ABAQUS: create initial model apply boundary conditions apply material properties (including those of the interface) any of the other cool stuff that ABAQUS does FRANC3D: insert arbitrary 3D crack (re)mesh at crack growth/insertion (including interface element insertion) compute growth parameters and grow (need some criteria)