SUBCRITICAL CRACK-GROWTH BEHAVIOR OF BOROSILICATE GLASS UNDER CYCLIC LOADS - EVIDENCE OF A MECHANICAL FATIGUE EFFECT

Citation
Sj. Dill et al., SUBCRITICAL CRACK-GROWTH BEHAVIOR OF BOROSILICATE GLASS UNDER CYCLIC LOADS - EVIDENCE OF A MECHANICAL FATIGUE EFFECT, Journal of the American Ceramic Society, 80(3), 1997, pp. 773-776
Citations number
23
Categorie Soggetti
Material Science, Ceramics
ISSN journal
00027820
Volume
80
Issue
3
Year of publication
1997
Pages
773 - 776
Database
ISI
SICI code
0002-7820(1997)80:3<773:SCBOBG>2.0.ZU;2-Z
Abstract
Amorphous glasses are generally considered immune to mechanical fatigu e effects associated with cyclic loading. In this study surprising new evidence is presented for a mechanical fatigue effect in borosilicate glass, in both moist air and dry nitrogen environments. The fatigue e ffect occurs at near threshold subcritical crack-growth rates (da/dt < 3 x 10(-8) m/s) as the crack extension per cycle approaches the dimen sions of the borosilicate glass network. While subcritical crack growt h under cyclic loads at higher load levels is entirely consistent with environmentally assisted crack. growth, lower growth rates actually e xceed those measured under monotonic loads. This suggests a mechanical fatigue effect which accelerates subcritical crack-growth rates. Like ly mechanisms for the mechanical fatigue effect are presented.