In Situ Formation of Strain Sensors by Breaking Optical Fibers in Structural Materials

Abstract

This article describes the formation of strain sensors embedded in a matrix material by breaking a notched optical fiber in the matrix. When a specimen with an embedded optical fiber with a notch is tensile tested, fracture of the fiber at the notch occurs, producing an optical interference type strain sensor. During the formation process optical transmission loss is recorded. The case of multiply notched optical fibers is also considered and it is shown that the optical loss of the embedded optical fiber during tensile test increases with the number of breaks. Using bending, instead of tension, to form the sensor, allows a reduction of break pitch and consequently improves the local nature of the sensor. The multiple fractured type optical fiber sensor has also been used on an active laminate to monitor its curvature change during actuation.KEY WORDS: smart material, optical fiber, composite, strain sensor, active material.

Simultaneous measurement of optical and dynamic mechanical properties of plastic optical fibers

“…The major source of optical loss in POF are intrinsic factors such as absorption (higher harmonics of C-H absorption and electronic transitions absorption) and Rayleigh scattering. During their practical operations environmental factors and mechanical stresses bring both physical and chemical changes of core material and cause change in optical transmission [4][5][6].…”

A New Designing Concept for Multifunctional Structural Material Systems Based on Composites

“…So if they are combined together to make a composite, the similar properties, normally high mechanical property, can be maintained, a nd the other dissimilar properties conflict with each other, which w ill successfully generate functional properties without using any sophisticated functional materials. In order to validate this concept, two examples, that is, CFRP/Al active laminate [5][6][7][8][9] and Ti fiber/Al multifunctional composite [10] are introduced in this paper.…”