Temperature Dependence of Static Fatigue of Optical Fibers Coated with a Uv‐Curable Polyurethane Acrylate

The static fatigue of fused silica optical fibers coated with a uv‐curable polyurethane acrylate was measured, in water, from 40° to 90°C in 10° C intervals. The usual log (time‐to‐failure) vs log (applied stress) plotting of the data gives a bilinear fit at all test temperatures examined. By assuming exponential temperature dependence for static fatigue parameters, empirical static fatigue equations are generated for the two straight‐line segments. These equations are then used to generate a static fatigue design diagram at a given temperature. In view of the possible coating effects on static fatigue, these results should be cautiously applied to optical fibers coated with other polymers.