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~s^η and η=0.48±0.03 with η=0.48±0.03 and μ=0.50±0.03. When the mass density is reduced to 1.4 g/cm³, the pores grow catastrophically to cause fracture. The roughness exponent for fracture surfaces, α=0.87±0.02 supports experimental claims about the universality of α.