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.
The kinematic and dynamic characteristics and system optimization design of optical cable based on backtracking method
Optical cable in modern communications is an important facility, and the laying of the optical cable is the key link in the installation. On the basis of analyzing the technological process and ensuring the requirements of optical cable laying, the kinematic parameters the tractor was first optimized and determined by the simplex method. analyzing the motion state and stress state of optical cable laying. E exponential function was selected as the movement mode of the cable to start and stop the cable. The kinematic characteristics of optical cable were programmed with the simplex method, and the optimal acceleration, uniform speed and deceleration distance were obtained corresponding to the three stages. Then the ideal parameters of cable cable’s velocity and acceleration were determined. According to this, the angular acceleration as well as other kinematic and dynamic characteristics of the roller slip roller was obtained ensuring these parameters being in coalescence with those of the tractor. The application study has shown that the system works well and meets the design expectation.
Static and Dynamic Fatigue of a Polymer‐Coated Fused Silica Optical Fiber
The dependence of fracture strength on tensile strain rate (dynamic fatigue) was used to establish the characteristic slow-crack-growth parameters in ethylene vinyl acetate-coated optical fibers. Strength was measured with five strain rates at each of four relative humidities (from 2 to 97% rh) on specimens 5 cm long. The inert fracture strength was measured at a low temperature in a dry atmosphere. The results of these tests were incorporated into a fracture mechanics model, including slow crack growth, for static fatigue. An increase in relative humidity promotes dynamic fatigue and leads to a predicted acceleration of static fatigue. Measurements of the static fatigue time-to-failure at three applied stress levels (on specimens 61 cm long) in 97% rh agree with the predicted behavior based on dynamic fatigue. The applicability of fracture mechanics crack-growth laws to fused silica fibers is discussed in terms of the Charles and Hillig stress-corrosion model.