A multiscale model for amorphous materials
S Urata and SF Li, COMPUTATIONAL MATERIALS SCIENCE, 135, 64-77 (2017).
In this work, we proposed a Cauchy-Born rule (CBR) based multiscale model to study mechanical properties of amorphous materials. In this work, we combine a coarse-grained Parrinello-Rahman (CG-PR) method and the Multiscale Cohesive Zone Model (MCZM) method to model the Lennard- Jones (L-J)binary glass and amorphous silicon (a-Si) solid. The proposed CG-PR method applies the CBR to a representative volume element of an amorphous material with representative microstructure pattern, whose side dimension is about twice of the cutoff distance of interatomic interaction. Numerical simulations were carried out, and it is found that CG-RP method can reproduce the stress-strain relations extrapolated from large scale MD simulations for both L-J binary glass as well as amorphous silicon (a-Si). TheCG-PR method is then combined with MCZM method to simulate failure process of amorphous materials. We found that (1) the CG-PR method can capture the history-dependent inelastic stress strain relation in amorphous materials, and (2) the CG-PR enhanced MCZM method can simulate both brittle and ductile fracture in both a-Si solid and L-J binary glass. Moreover, the multiscale methodology developed here may be extended to study mechanical properties of a variety of other non-crystalline materials. (C) 2017 Elsevier B.V. All rights reserved.
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