THE EFFECT OF UV-RADIATION ON THE MECHANICAL STRENGTH OF AS2SE3 GLASS-FIBERS

This paper presents tensile strength data for As2Se3 glass fibers stored for a period of 30 days under a combination of UV light, complete darkness, moisture and vacuum. The strength statistical distributions were analyzed by both the Weibull and fundamental approaches, the latter assuming no specific functional form for the flaw density distribution. It was found that the fiber strengths deteriorated due to the action of UV light. The combined effect of UV light and humidity was found to lead to enhanced degradation. However, fibers stored under high humidity in complete darkness exhibited superior mechanical properties. The mechanisms responsible for these observations are discussed with regard to the surface topographical changes. Fracture surface specimens were analyzed from all the fiber groups investigated. Plots of log tensile strength versus log mirror radius yielded straight line plots distinctly different for irradiated and unirradiated fiber groups. Approximate values obtained for the critical stress intensity factor, K(IC), were 0.16 and 0.25 MPa m0.5 for irradiated and unirradiated fiber groups, respectively. The significance of these results is discussed.