The multiple shear bands and plasticity in metallic glasses: A possible origin from stress redistribution

Here we present a finite element method simulation to investigate the shear band multiplication process in metallic glasses. The simulation demonstrates that the stress field would redistribute after the former shear band formation and sliding, where higher stress is reached at the direction perpendicular to the original shear band. In the simulation, a shear offset of several microns will cause a stress inhomogeneity of tens of MPa, which is comparable to the magnitude of shear softening effect in the original shear band, and could trigger the formation of new shear bands. The simulated shear-offset and shear band intersection morphologies consist well with experiments. These results reveal a possible mechanism of stress field redistribution during the shear band multiplication process in metallic glasses, and reasonably explain the dependence of plasticity of metallic glasses on both material and loading conditions. Based on these findings, the affecting factors including the constraint loading condition, sample size and shape on shear band multiplication process in metallic glasses are also discussed. (C) 2016 Elsevier B. V. All rights reserved.