Structural Health Monitoring Using a New Type of Distributed Fiber Optic Smart Textiles in Combination with Optical Frequency Domain Reflectometry (OFDR): Taking a Pedestrian Bridge as Case Study

Abstract

Distributed fiber optic sensors (DFOS) have become a new method for continuously monitoring infrastructure status. However, the fiber’s fragility and the installation’s complexity are some of the main drawbacks of this monitoring approach. This paper aims to overcome this limitation by embedding a fiber optic sensor into a textile for a faster and easier installation process. To demonstrate its feasibility, the smart textile was installed on a pedestrian bridge at the University of Massachusetts Lowell. In addition, dynamic strain data were collected for two different years (2021 and 2022) using Optical Frequency Domain Reflectometry (OFDR) and compared, to determine the variability of the data after one year of installation. We determined that no significant change was observed in the response pattern, and the difference between the amplitude of both datasets was 14% (one person jumping on the bridge) and 43% (two people jumping) at the first frequency band. This result shows the proposed system’s functionality after one year of installation, as well as its potential use for traffic monitoring.

Smart finger posture real-time monitoring system

“…The optical fiber strain sensor used by OFDR system was fabricated following the manual as shown in Figure 1. 16 A low bend loss (LBL) single-mode fiber (SMF) with polyimide coating (SMF-37-p-125-3, AFL) was used as the sensing part. The length of fiber can be adjusted and customized according to the pattern design or environment requirements.…”

Temperature insensitive distributed wide-dynamic-range strain sensing based on polarization-maintaining photonic crystal fiber

“…time domain reflectometry, which has great potential in highprecision instrument detection, biomedicine, and aerospace fields. Especially, it can be applied to the structural health monitoring of buildings, bridges, tunnels and new energy vehicle batteries [7][8][9] with the corresponding distributed strain measurements. Wide-dynamic-range strain sensing with high spatial resolution is essentially corresponding to large structure deformation, which is more common in potential structural problems, thus its importance is obvious to reduce the risk of accidents in advance.…”

Activation Function Dynamic Averaging as a Technique for Nonlinear 2D Data Denoising in Distributed Acoustic Sensors

“…Each of them must be identified by frequency and spatial coordinate. Together with other reflectometric methods that study slowly changing physical quantities in new materials and structures [17][18][19][20], distributed acoustic sensors for flaw detection problems form a complete understanding of the object's behavior in a wide range of external conditions [21,22]. Thus, in [21], distributed acoustic monitoring was used to study the operating regimes of a gas turbine.…”