A Textile Embedded with Distributed Fiber Optic Sensors for Pedestrian Bridge Monitoring

This paper explores the use of distributed fiber optic sensors for Structural Health Monitoring (SHM) as a mechanism for the continuous and accurate monitoring of civil infrastructure. Distributed fiber optic sensors are advantageous as they are distributed throughout the structure reducing the cost of single discrete sensor installation. Moreover, the nature of fiber optic sensor’s immunity to electromagnetic interference and light weight makes them suitable to install in any environmental situation. In previous work, fiber optic sensors were used for SHM, but they are not fully integrated with infrastructure. To overcome this limitation, in this paper, textile embedded distributed fiber optic sensor is implemented which not only provide rigidity to install in the structure such as pedestrian bridge, but also provide continuous data along the fiber cable due to its distributed nature. This distributed textile-embedded sensor was installed on a pedestrian bridge at the University of Massachusetts Lowell. This 28m installed sensor can detect vibration when there is any load in the bridge. To ensure its functionality, this paper presents strain change data corresponding to when one person walked on the bridge and the data were collected using Optical Frequency Domain Reflectometry (OFDR). The strain change data with one person walking along the bridge ensures that this sensor can sense even a minimal load and it can record continuously distributed data along the fiber optic cable. This type of distributed fiber optic sensor can be used for continuous data collection of any civil infrastructure with vibration change detection which will help to diagnose if any damages occur in the structure.