Monitoring of pipelines subjected to interactive bending and dent using distributed fiber optic sensors

Interactive anomalies of pipelines represent important contributors to pipeline incidents, but monitoring interactive anomalies is challenging. This paper presents an approach to monitor interactive bending and dent deformations that occur at the same pipeline section. The proposed approach utilizes distributed fiber optic sensors to measure strain distributions of pipelines with a high resolution (0.65 mm) in real time. Steel pipes instrumented with fiber optic cables along their length and circumference directions were tested under four-point bending to generate interactive bending and dent deformations. The strain distributions measured from the distributed sensors were analyzed to detect, locate, quantify, visualize, and distinguish interactive bending and dent deformations in the loading process. The strains measured from distributed fiber optic sensors aligned with those measured from fiber Bragg grating sensors, displacement sensors, and computer vision. This study enhances the ability to monitor interactive threats in pipelines, contributing to improved condition assessments and infrastructure resilience.