Distributed Strain Sensing from Different Optical Fiber Configurations

Daniel Drake,J Wilson,Rani Sullivan

doi:10.3390/inventions3040067

Abstract

Strain distributions were obtained from optical fibers arranged in three different configurations on transversely-loaded cantilevered beams. Traditional strain measurement sensors, such as strain gauges, are limited to measuring strain at discrete points on a structural member. However, distributed optical fibers can measure high spatial (<1 mm spacing) strain or temperature distributions. In this study, optical fibers in spiral, grid, and rosette configurations were bonded to aluminum cantilevered beams subjected to tip loads. Strain distributions from optical fiber sensors were measured using a swept wavelength coherent interferometric technique. The optical fiber strain measurements show good agreement with strain gauge measurements. The attributes of each sensor configuration are discussed.

Highlights

Traditional methods to measure strain such as foil strain gauges are commonly used on large scale structural tests
They are limited to measuring strain at discrete locations
Novel approaches using optical fibers have been developed to measure large and high-spatial distributions of strain. These optical fibers can be embedded within composite structural aircraft components

Summary

Introduction

Traditional methods to measure strain such as foil strain gauges are commonly used on large scale structural tests. They are limited to measuring strain at discrete locations. Novel approaches using optical fibers have been developed to measure large and high-spatial distributions of strain. These optical fibers can be embedded within composite structural aircraft components. Minakuchi et al [1] monitored the entire life-cycle of a component structural panel using a fiber-optic-based Brillouin scattering technique. It was determined that a single embedded optical fiber could monitor the internal strain from the manufacturing process and post impact tests [1]

Methods

Results

Conclusion