Molecular dynamics of stress-strain behaviour of silica glass under tensile load.

Molecular dynamics (MD) simulations were carried out to study the stress-strain diagrams of crystallineand amorphous silica under different nonequilibrium conditions. The responses of a tensile load wererecorded 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 perpendicularto the strained one. The higher strength of crystalline silica as compared to amorphous silica resultedfrom a different distribution of ring sizes. The results obtained for the inert failure strains and intrinsicstrength of the silica glass were in good agreement with the experimental data, and the nonlinear elasticbehavior 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 calculatedby means of static methods and with experimental data.