Fused glasses (fused quartz and fused silica) are materials of much value in many technological applications. In addition to outstanding optical properties, fused has a very low coefficient of thermal expansion, which makes it highly attractive for designing optical components such as laser windows.1 For this reason, it is essential to thoroughly investigate key features relating to the flexural strength, especially how stressed area and surface finish impact the mechanical performance. Readily available literature does not go beyond reporting mean strength values (or modulus of rupture) of (Ref. 2)—or (Ref. 3)—and a Weibull shape parameter of 4 to 5 (Ref. 4). Very recently, this situation has drastically improved in view of a comprehensive investigation that was carried out at the University of Dayton Research Institute5 (UDRI); this investigation includes rich sets of fracture-stress measurements performed in conjunction with detailed assessments of the surface finish of tested specimens. In this paper, we document the results of an analysis of the UDRI data—an analysis based on Weibull’s theory of brittle fracture6—and clarify issues relating to the failure probability dependence on biaxial tensile stresses, taking into consideration the stressed area as well as the surface finish.
© 2009 Society of Photo-Optical Instrumentation Engineers
Claude A. Klein
"Characteristic strength, Weibull modulus, and failure probability of fused silica glass", Opt. Eng. 48(11), 113401 (November 25, 2009). ; http://dx.doi.org/10.1117/1.3265716