The usefulness of glasses, and particularly of metallic glasses, in technological applications
is often limited by their toughness,(which is defined as the area under the stress vs. strain
curve before plastic yielding). Recently, toughness was found to increase significantly by the
addition of small concentrations of foreign atoms that act as pinning centers. We model this
phenomenon at zero temperature and quasi-static straining with randomly positioned
particles that participate in the elastic deformation, but are pinned in the non-affine return to …