High resolution, dynamic strain measurements with continuous fiber Bragg gratings for structural health monitoring

Abstract

We describe the use of swept-wavelength interferometry (sometimes referred to as optical frequency domain reflectometry, OFDR) for high speed, distributed fiber-optic sensing. The technique utilizes continuous gratings written in single mode fiber facilitating high density distributed measurements of temperature or strain up 1 millimeter resolution. The technology used herein is capable of strain measurement rates of up to 1 KHz over the measurement domain with millimeter resolution. This technique shows great utility as a method for dynamic structural health monitoring, model simulation validation for mechanical prototypes, vibration monitoring or closed loop feedback control for process optimization.