  In this paper we study the mechanical properties and pore structure in a
three-dimensional molecular dynamics model of porous glass under athermal
quasistatic shear. The vitreous samples are prepared by rapid thermal quench
from a high temperature molten state. The pore structures form via solid-gas
phase separation. The quiescent samples exhibit a wide range of pore
topography, from inter-connected pore network to randomly distributed compact
pores depending on the material density. We find the shear modulus strongly
depends on the density and porosity. Under mechanical loading, the pore
structure rearranges which is reflected in the pore size distribution function.
Our results show that with increase in strain the distribution widens as the
adjacent pores coalesce and form larger pores. We also propose a universal
scaling law for the pore size distribution function which offers excellent data
collapse for highly porous materials in the undeformed case. From the data
scaling we identify a critical density which can be attributed to the
transition point from a porous-type to bulk-type material. The validity of the
scaling law under finite deformation is also analyzed.
