As Plasticity involves phenomena at multiple scales, there has been many approaches explored to transfer qualitative and quantitative informations through scales.
We propose a novel approach to the transfer of slip accross interfaces to bridge the atomic-scale with the contimuum-scale. In particular, we relie on the determination of the properties of the dislocations and interfaces that can be transfer to higher-scale/continuum models. As an example, Fig. 1 shows the determination of the equivalent Burgers vector for an dislocation absorbed at an interface (here, a pure twist grain boundray). By applying an appropriate laod, the dislocation will initiate a slip transfer to the neigboring grain, which will depend on the properties of system "dislocation/interface".
Fig. 1: Excess in strain energy of a dislocation (edge or screw) absorbed at a high angle symetric Σ19 twist grain boundary. Determination of the associated Burgers vector. [unpublished work]
Within the context of damage induced by focused ion beam (FIB) irradiation in silicon, we propose a scale-bidging approach to transfer strain information from the atomic-scale to the meso-scale.
In particular, the concept of eigenstrain offers a versatile generic framework for the description of inelastic deformation that acts as the source of residual stresses. FIB milling used for nanoscale machining is accompanied by target material modification by ion beam damage having residual stress consequences that can be described in terms of eigenstrain. Due to the lack of direct means of experimental determination of residual stress or eigenstrain at the nanoscale, we adopt a hybrid approach that consists of eigenstrain abstraction from molecular dynamics simulation, its application within a finite element simulation of a flexible silicon cantilever, and satisfactory comparison of the prediction with experimental observation.
Fig. 2: The illustration of (a) molecular dynamics model setup for the simulation of grazing ion irradiation, and (b) depth profile of irradiation induced strain as determined by atomistic calculation.
[From Korsunky, Guénolé et al., Materials Letters 185 (2016) 47-49]