Reliability and features of optical cable laying
We study the dependence of the optical fibre lifetime on the tension. A method for calculating the elongation of the optical fibre depending on the bending radius is proposed. Recommendations on the bending radius choice of the fibre in the design of optical networks to increase their reliability are given.
Failure prediction for long length optical fiber based on proof testing
A new method for reliability assurance of long length optical glass fibers is presented. This method is based on a simple equation by fracture‐mechanics theory and provides failure probability prediction for fibers after proof testing. The prediction is made by using dynamic fatigue data obtained by simple tensile tests and failure number during proof testing. The experimental results are found to be in good agreement with those predicted by the theory, and it is verified that the method is useful to make reliability assurance of long optical fibers for long‐ term use.
Silicone- and ethylene-vinyl-acetate-coated laser-drawn silica fibres with tensile strengths >3.5 GN/m2 (500 kp.s.i.) in >3 km lengths
Tensile strength measurements have been made on fused silica fibres coated with a silicone resin or an ethylene-vinyl-acetate (e.v.a.) hot-melt adhesive. The average strength measured in 20 m guage lengths was 4.7 GN/m2 (671 kp.s.i.) for 3 km of silicone-coated fibre and 5.2 GN/m2 (743 kp.s.i.) for 3.6 km of the e.v.a.-coated fibres. Although control of many drawing and coating process parameters is required to achieve these strengths, the results suggest that under similar conditions other coating systems may perform equally well.