Mechanical properties and pore size distribution in athermal porous glasses

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 quenching 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 networks to randomly distributed compact pores depending on the material density. We find that 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 that 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.

Automated summary

The mechanical properties and pore structure of porous glass under athermal quasistatic shear were studied. It was found that the shear modulus strongly depends on density and porosity, and the pore structure rearranges under mechanical loading, reflected in changes to the pore size distribution function. A universal scaling law for the pore size distribution function was proposed, showing data collapse for highly porous materials in the undeformed case. Additionally, a critical density was identified as the transition point from porous-type to bulk-type material. The validity of the scaling law under finite deformation was also analyzed.