An Adaptive Multiscale Method for Quasi-static Crack Growth

in Computational Mechanics (2013)

This paper proposes an adaptive atomistic-continuum numerical method for quasi-static <br />crack growth. The phantom node method is used to model the crack in the continuum region <br />and a molecular ... [more ▼]

This paper proposes an adaptive atomistic-continuum numerical method for quasi-static <br />crack growth. The phantom node method is used to model the crack in the continuum region <br />and a molecular statics model is used near the crack tip. To ensure self-consistency in the bulk, <br />a virtual atom cluster is used to model the material of the coarse scale. The coupling between <br />the coarse scale and ne scale is realized through ghost atoms. The ghost atom positions are <br />interpolated from the coarse scale solution and enforced as boundary conditions on the ne <br />scale. The ne scale region is adaptively enlarged as the crack propagates and the region behind <br />the crack tip is adaptively coarsened. An energy criterion is used to detect the crack tip loca- <br />tion. The triangular lattice in the ne scale region corresponds to the lattice structure of the <br />(111) plane of an FCC crystal. The Lennard-Jones potential is used to model the atom-atom <br />interactions. The method is implemented in two dimensions. The results are compared to pure <br />atomistic simulations; they show excellent agreement. [less ▲]