Macrobending loss in fiber optic wrapped on rubber-spring wire structure under static load-pressure

Abstract

This work observes rubber-based frame structures for wide helix-shaped-macrobending fiber optic sensors intended for measuring an object with high load levels. In this fiber sensor, the working principle is to measure the power loss (due to bending) of the light traveled in the employed fiber optic. During the applications, it needs a particular mechanical structure to accommodate a reversible fiber bending in the context of load measurement. In this work, a cylindrical-shaped rubber structure mixed with calcium carbonate compound (CaCO3) is constructed as the fiber bending frame (housing) in which a spring wire is inserted into the structure in the two models, i.e., outer and inner-spring structure. Several investigations of static load pressure reveal the optimum structure design for high load measurement. Using the inner-spring model, a rubber structure with 10wt% CaCO3 exhibits the preferable performance with a sensitivity of 0.15 V/Kg.cm2 and measurement load range until 210 Kg.