Dynamic Crack Propagation Using a Combined Molecular Dynamics/Extended Finite Element Approach

A method is presented for simulating dynamic crack propagation using a coupled molecular dynamics/extended finite element method. Molecular dynamics is used at the crack tip while the extended finite element method naturally models the crack in the wake of the tip as a traction-free discontinuity. After recalling the basic molecular dynamics equations, the discretization of the continuum and the traction-free discontinuity via the extended finite element method, and the zonal coupling method between both domains, two-dimensional computations of dynamic fracture are presented, including a discussion on how to move and/or expand the zone in which molecular dynamics is used upon crack propagation