Growth of Pore Interfaces and Roughness of Fracture Surfaces in Porous Silica: Million Particle Molecular-Dynamics Simulations

Pore interface growth and the roughness of fracture surfaces in silica glasses have been investigated with large-scale molecular-dynamics simulations. During uniform dilation, the average pore radius $R$ and the width $W$ scale with the pore size $s$ as $R\sim s^{\eta }$ and $\eta =0.48\mathrm{}\pm 0.03$ with $\eta =0.48\mathrm{}\pm 0.03$ and $\mu =0.50\mathrm{}\pm 0.03$. When the mass density is reduced to 1.4 g/${\mathrm{cm}}^3$, the pores grow catastrophically to cause fracture. The roughness exponent for fracture surfaces, $\alpha =0.87\mathrm{}\pm 0.02$ supports experimental claims about the universality of $\alpha$.