Strength and fatigue of multicomponent optical glass fibres

Abstract

Strength and fatigue of multicomponent glass fibres have been measured as a function of environment and glass composition. Strength and dynamic fatigue were measured using a two-point bending technique from − 196 to 100‡ C and also in vacuo down to 10−5 torr. Zero stress ageing and static fatigue have been measured in ambient air and water at 20‡ C for different glass compositions. The addition of zinc, magnesium and aluminium oxides to sodium borosilicate glasses were shown to give significant improvements to the corrosion behaviour and a glass has been developed which could survive in water for longer than 7×103 h at strains greater than 1%. Finally a modified theory of static fatigue has been outlined in order to explain the departure from conventional stress corrosion theory that was evident in some glass compositions.