Orientation of silica rings under uniaxial stress in simulated vitreous silica

We present simulations by Molecular Dynamic of a distorted silica glass. Uniaxial stresses at constant volume have been applied at temperature higher and lower than the temperature Tg of the vitreous transition. These conditions would simulate the extrusion of fibers. In order to understand the effect of the applied stress on the structure we have checked the orientation of silica rings of small order. Three and 4-fold rings can be easily detected by Raman spectroscopy. Due to their rigidity we expect a more important sensitivity to reorientation of low order rings. We observe in our simulated samples at the lower temperature an important increase of the number of 3-fold rings and a tendency to their orientation.