XFEM-dislocation dynamics multi-scale modeling of plasticity and fracture

An extended three-dimensional multi-scale framework is presented to model plasticity in precipitate containing materials in the presence of cracks. The present framework is constructed in two scales. At the micro scale, plasticity is computed via the line dislocation dynamics (DD) methodology in which the penetrable and impenetrable precipitates are modeled. At the macro scale, application of the extended finite element method (XFEM) allows for accurate analysis of mixed-mode cohesive crack propagation without the need for any remeshing procedure. This is a significant improvement especially when two different scales are involved. While the former simulations have so far been limited to the study of only mode-I crack propagation to avoid the expensive remeshing procedure, in the present work, the effects of loading rates and precipitate density on general crack propagations are studied by utilizing the XFEM-DD multi-scale framework to illustrate the efficiency and capability of the proposed approach.