The goal of this project is to optimize the existing optical frequency-domain reflectometry (OFDR) method to facilitate dynamic structural health monitoring using Distributed Optical Fiber Sensors (DO..
The goal of this project is to optimize the existing optical frequency-domain reflectometry (OFDR) method to facilitate dynamic structural health monitoring using Distributed Optical Fiber Sensors (DOFS) under field conditions. These sensors offer a cost-effective solution that reveals temperature, strain, and vibration information from any point along the entire length of an optical fiber. However, one of the biggest challenges that hinder the wide implementation of DOFS is the dynamic monitoring capability under field conditions. Most preliminary studies using DOFS have been done in perfect laboratory conditions. Although several efforts have been made to improve the dynamic monitoring capability of DOFS using polarization-optical time-domain reflectometry (OTDR), OTDR is limited to a spatial resolution of ~1m. Optical frequency-domain reflectometry (OFDR) technique offer high spatial resolution and easy setup for stationary measurements. If similar performance can be achieved under dynamic monitoring conditions, OFDR can be implemented in virtually any SHM application. This study aims at developing an optimized OFDR for dynamic monitoring using DOFS under field conditions. Advanced algorithms have been developed for spectral analysis along with new de-noising methods. A laboratory experimental program was conducted testing reinforced concrete beams under a 4-point loading test well as a field monitoring program was carried out to validate static and dynamic measurements with conventional sensors, respectively. For both methods, results between the sensors and traditional monitoring techniques have been very close in comparison.