Effect of water on brittle fracture of SiO2 by molecular dynamics study

The influence of water on the brittle behavior of β-cristobalite is studied by means of molecular dynamics (MD) simulation with the TTAM potential. Crack extension of mode I type is observed as the crack opening is filled up with water. The critical stress intensity factor KIcMD is used to characterize the crack extension of MD simulation. The surface energy of SiO2 covered with layers of water is calculated at temperature of 300 K. Based on the Griffith fracture criterion, the critical stress intensity factor KIcGriffith is calculated, and it is in good agreement with that of MD simulation.