High-sensitivity structure based on fiber Bragg grating sensor and its application in nonintrusive detection of pipeline pressure change

Pressure pipelines are widely used in many industry fields. To ensure the safe and stable operation of pipeline transportation, the pressure detection is necessary. In this study, a nonintrusive high-sensitivity sensitization structure for pipeline pressure detection is proposed based on fiber Bragg grating (FBG) sensor. Firstly, the relationship between the strain of pipeline wall and pipeline internal pressure is established. Then, by employing hinge-lever, a novel strain-amplifying structure with FBG sensor is developed to effectively transmit and amplify the pipeline wall strain. The sensitivity analyses of the sensitization structure are derived and a series of structural optimization are carried out. To validate the feasibility of the proposed structure, experiments are carried out and the results show that the sensitization structure has a remarkable stability and effective transmission with an amplification coefficient of 4.75 times. The proposed structure has a potential application prospect for pressure monitoring of oil and gas pipelines.