<title>Etched fiber optic sensing network in smart composite structures and its signal processing technology</title>

Abstract

A three dimension sensing network, which is composed of periodically etched multi-mode optical fibers, is embedded in the laminated composite material structure of vertical tail-wing of plane for nondestructive evaluation of structural states in smart composite material and structures. The composite specimens in which sensing network is embedded are tested with stretching, bending and impacting. It is exhibited in the experiment that the responses of fiberoptic sensor are linear, repeatable, have a high sensitivity and no measurable hysteresis. The experimental results have shown the feasibility of embedded fiberoptic sensor network to be used to measure the structural states such as strain, stress and damage. The signal processing for the parallel and distributing fiberoptic sensing network by using artificial neural network is also described. In this paper, the BP network which is suitable for distributing sensing signal processing is studied, and the simulation has demonstrated that the BP network's ability for identifying the position of stress, strain and damage is above 90%.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.