Consequence of Damage in Silica on Young’s Modulus

Water diffusion into silica glass results in a thin zone near the surface of the glass. In this zone the water reacts with the SiO₂ structure and “damages” the originally intact SiO₂ rings. The consequence is a reduced Young’s module. This effect can be described by use of continuum damage mechanics according to Kachanov and Lemaitre. The amount of damage can be estimated from literature data on sound velocity measurements.