Atomistic-to-continuum description of edge dislocation core: unification of the Peierls-Nabarro model with linear elasticity
Conventional linear elasticity theory predicts the strain fields of a dislocation core to diverge, whereas it is known from atomistic simulations that strains at dislocation cores remain finite. We present an analytical solution to a generalised, variational Peierls-Nabarro model of edge dislocation displacement fields that features a finite core width, as well as the correct isotropic elastic behaviour at large distances away from the core. The strain fields are in qualitative agreement with atomistic simulations of 1/2 [111](10-1) edge dislocations in bcc tungsten and iron. The treatment is based on the Multi-String Frenkel-Kontorova model that we reformulate as a generalization of the Peierls-Nabarro model using the principle of least action.