Molecular Dynamics Studies of Stress−Strain Behavior of Silica Glass under a Tensile Load

Abstract

Molecular dynamics (MD) simulations were carried out to study the stress−strain diagrams of crystalline and amorphous silica under different nonequilibrium conditions. The responses of a tensile load were recorded in two cases. In one case, the system was not allowed to relax along the transverse direction (null Poisson’s ratio), while in the other case, the deformations were allowed in directions perpendicular to the strained one. The higher strength of crystalline silica as compared to amorphous silica resulted from a different distribution of ring sizes. The results obtained for the inert failure strains and intrinsic strength of the silica glass were in good agreement with the experimental data, and the nonlinear elastic behavior of the glass was reproduced along with the effects of strain rate and temperature variation. Elastic properties extracted from stress−strain diagrams also were compared with the properties calculated by means of static methods and with experimental data.