At the continuum level, slip transfer across grain boundaries is usually resolved through geometric arguments, whilst the dislocations remain Volterra singularities, and their interactions are assumed to be based on the linear elastic considerations that govern conventional dislocation dynamics. In this talk, we use the Kanzaki force formulation introduced in [1,2] to develop an atomistically informed continuum level model of the dislocation core as the latter approach a grain boundary. The approach enables us to develop non-phenomenological models of the dislocation core at the continuum model that accurately map the core structures obtained in atomistic simulations of molecular dynamics. Because the core structure is observed to change as the dislocation interacts with the grain boundary, the Kanzaki force model of the core offers a promising and computationally inexpensive way of modelling short range details of slip transfer. We implement the model into conventional dislocation dynamics, which we use to study the implications the observed atomistic non-linearities may have in the formation and collapse of dense dislocation pile-ups at grain boundaries. Results for pile-ups in bicrystalline cubic metals will be discussed.
References:
[1] Gurrutxaga-Lerma & Verschueren, Physical Review B 98 (13), 134104, 2018.
[2] Gurrutxaga-Lerma & Verschueren, Physical Review Materials 3 (11), 113801, 2019.
