Mechanical fatigue of silica glass

Abstract

It was shown that the thermally or chemically treated SiO2 glass can have cracks with blunt tips. The mechanical fatigue behavior of the specimens with blunt cracks was different from that of the freshly abraded specimens. This difference can best be explained by postulating that the fatigue of the specimens with blunt cracks involves crack initiation, in addition to crack growth while that of the specimens with sharp cracks involves only the crack growth. It was also shown that crack initiation under sub-critical stress requires the presence of a special medium such as water which can enter the glass under stress. © 1987 Elsevier Science Publishers B.V.