Creating Atomic Models of Brittle Glasses for In Silico Mechanical Tests.

Atomic level computer simulation has become indispensable in understanding the mechanical properties of glasses, among other properties. However, the majority of model glasses are more ductile than their intended experimental counterparts, partially reflected by the overestimation of the Poisson's ratio. We have previously introduced an effective force field tuning method of imposing an additional energy penalty term to embrittle a binary Lennard-Jones glass. Here, we improved this method by varying the applied range of the energy penalty. The new method stabilizes the model glass even for high energy penalty values. Furthermore, unlike the old method, there is no unintended reduction in density for brittle glasses. Uniaxial tension tests were conducted to show the ductile-to-brittle transition as the energy penalty increases in strength. Crack propagation simulation was also conducted to demonstrate the efficacy of studying brittle fracture using the model glass. [ABSTRACT FROM AUTHOR]