<title>Transverse loading effects on embedded Bragg fiber system</title>

Abstract

Optical fibers imprinted with a Bragg grating, a periodic change in the refractive index of the core of the fiber, can be used as strain gages in structural health monitoring. It is well known that fiber Bragg grating (FBG) structures can be applied as optical strain gages with very high sensitivity and reasonable accuracy. This application has been confirmed through numerous publications on the effect of axial loads on FBG structures. The FBG structure can easily be calibrated as an axial strain sensor. There are currently some trial applications ofthese optical strain gauges in bridge construction. However, using these FBG structures as embedded sensors has raised questions about sensor accuracy and measurements because of the Poisson's effect and/or application under multi-axial stress states. Therefore, the objective of this research was to study the effect of transverse loads on FBG structures for a better understanding of the interaction of the structure and the embedded Bragg fiber sensor output.