Contact‐Induced Static Fatigue of Annealed and Tempered Glass

Abstract

The role of environmentally assisted crack growth in the contact‐induced strength degradation of brittle surfaces was studied. Indentation fracture mechanics, incorporating a standard crack‐velocity function, are used to predict remaining strength as a function of contact load and duration. Strength tests on annealed and tempered glass disks, indented with a diamond pyramid or tungsten carbide sphere in a water environment, are in accord with the predicted degradation characteristics. The results indicate that fatigue effects are likely to be of only secondary importance in designing for maximum resistance to in‐service contact damage.