Abstract
Thermally tempered glass is made by cooling rapidly after heating float glass to near a softening point. The compressive residual stresses generated at the surface layer by thermal expansion make strengthen the material. However, the tensile residual stress layer will be also generated in the interior of the material to compensate for the surface compression residual stress. The presence of these residual stress layers in the thermally tempered glass will play an important role from the viewpoint of crack growth in fatigue. In this study, in order to examine the fatigue crack growth behavior of thermally tempered glass in detail, a simple and straight method suggested by Gupta was applied, where the crack size after indentation is measured by microscope directly. As a result, it was found that the surface compressive residual stress in thermally tempered glass not only strengthen but also restrain the crack growth.
