An FBG-based high-sensitivity structure and its application in non-intrusive detection of pipeline

Pipeline is one of the main transportation ways with increasingly wide applications in various fields. Generally, the pipelines are operated under high pressure, leakage accidents are extremely dangerous and it is necessary to ensure the safety of pipelines. In this study, a non-intrusive structure with high-sensitivity based on fiber Bragg grating (FBG) sensing is proposed for the detection of pipeline pressure. The core of the structure is a ditrigon strain beam that can transmit the strain on pipeline outside wall to the designed strain beam with an amplification function. Further, theoretical analyses for the structural sensitivity are deduced, and necessary structure optimization is implemented. To verify the practical function and effectiveness of the designed structure, laboratory experiments are conducted and the results indicate that the structure can amplify the strain on pipeline wall with an amplification coefficient of 5.44, and has the obvious advantages of convenient installation and simple-structure.