Molecular dynamics simulations of atomic-level brittle fracture mechanisms in amorphous silica

We have examined the atomic dynamics of the brittle fracture process in amorphous silica using molecular dynamics. Under strain, extensive atomic restructuring occur in the vicinity of voids leading to the formation of 2-membered (2-M) silica rings that are much different than the open network structure of the bulk. The sequence of events that lead to the formation of the 2-M rings was characterized by examining the change in local coordination of atoms.