Densification of window glass under very high pressure and its relevance to Vickers indentation

Window glass experiences permanent densification under high hydrostatic pressure, like amorphous silica but to a lesser extent. Comparable hydrostatic stresses are reached beneath a sharp indenter during indentation loading. The behavior of glass under very high pressure is therefore a key factor in understanding indentation deformation. A careful modelling of a Vickers indentation process, accounting for a newly determined pressure-densification constitutive law, allows for a quantitative estimation of the contribution of densification to the indentation strain.