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 similar to s(eta) and W similar to s(mu) with eta = 0.48 +/- 0.03 and mu = 0.50 +/- 0.03. When the mass density is reduced to 1.4 g/cm(3), the pores grow catastrophically to cause fracture. The roughness exponent for fracture surfaces, alpha = 0.87 +/- 0.02, supports experimental claims about the universality of alpha.