Modeling and numerical simulation of interfaces in polycrystalline materials (i.e. grain boundaries, sub-grain boundaries, twin boundaries), or interphases in materials subjected to phase transformation, is a primary topic in predicting/optimizing the mechanical response to complex thermomechanical loading, either when the ratio of interface area vs. sample volume becomes very large, as in nanostructured materials (metals, ceramics, etc.), or when dislocation-mediated plasticity is hampered by a lack of independent slip systems, as in certain geophysical materials (ice, olivine, etc.). In such conditions, interface-mediated plasticity may indeed become a prevalent deformation mechanism.
Interface modeling is naturally spanning length scales: when envisioned at macroscopic scale in polycrystalline simulations, interfaces are often seen as infinitely thin surfaces in large samples of engineering size, whereas they appear as finite layers between grains in fine scale models where their internal microstructure is described. Fortunately, recent progress in computing power, numerical methods and experimental techniques allow access to both local information in the material and accurate interface modeling at various resolution length scales. Nanoscopic/microscopic scale models include approaches such as Ab Initio calculations, Molecular Dynamics, Discrete Dislocation Dynamics, Continuous Dislocation/Disclination Dynamics and Phase Field approaches, and scale transitions with continuum mechanics models of crystal plasticity are badly needed.
Edited by: Claude Fressengeas, Stéphane Berbenni, and Ricardo Lebensohn