Prediction of stable crack growth geometry in residually stressed glass

Processing procedures have been developed that produce stress distributions in glass with a maximum compressive stress below the surface. These glasses can exhibit rising apparent fracture toughness behavior and reduced strength variability associated with the stable growth of surface cracks under applied tensile stress. A weight function approach was used to determine stress intensity factors as a function of crack geometry for surface cracks under the effects of stress distributions similar to those found in these glasses. These calculations were then used to predict the growth behavior of surface cracks as a function of the applied and residual stress fields.