Grain boundary energies and cohesive strength as a function of geometry

摘要: Cohesive laws are stress-strain curves used in finite element calculations to describe the debonding of interfaces such as grain boundaries. It would be convenient boundary cohesive a function parameters needed geometry; two dimensions and five three dimensions. However, we find that law is not smooth these parameters. In fact, it discontinuous at geometries for which grains have repeat distances rational with respect one another. Using atomistic simulations, extract energies fracture Lennard-Jones potential all possible can simulated within periodic conditions maximum box size. We introduce model where boundaries represented high symmetry decorated by extra dislocations. it, develop functional form symmetric energies, cusps angles. also asymptotic toughness near discontinuities using our dislocation decoration model.