Pressure pipeline crack identification method based on distributed optical fiber sensing technology

Abstract

The invention discloses a pressure pipeline crack identification method based on a distributed optical fiber sensing technology. The method comprises the following steps: S1, obtaining basic data information, material performance data information and damage tolerance information of a detected pressure pipeline; S2, simplifying the pressure pipeline structure and performing finite element analysisto obtain strain distribution information near a crack; S3, determining the layout scheme of distributed optical fiber sensors according to a finite element analysis result in S2; S4, performing a hydraulic experiment on the simplified pressure pipeline structure in a laboratory, collecting strain measurement data of the sensors under different loads, and calculating the conversion coefficient ofoptical fiber segment spacing; S5, pasting the distributed optical fiber sensors arranged circumferentially in the axial direction of the outer wall of the pipeline at an interval of d according to afabrication completion drawing of the pressure pipeline and the layout scheme of the distributed optical fiber sensors in S3 for real-time monitoring of the crack.

Description

technical field [0001] The invention relates to the technical field of structural monitoring, in particular to a pressure pipeline crack identification method based on distributed optical fiber sensing technology. Background technique [0002] The piping system is an important system for transporting working fluids in industrial equipment, such as the fuel system of aircraft, the braking system of vehicles, and the drainage system of ships, etc., all of which require complex piping systems to transport fluid media. During service, there is usually hydraulic shock accompanied by high-frequency pressure oscillations due to high pipeline pressure and large flow pulses. Therefore, the pressure piping system is prone to cracks. Failure to identify and locate pipeline cracks in a timely and accurate manner may result in pipeline rupture and major safety accidents. [0003] At present, the main technologies used for pipeline crack monitoring in the field of structural health moni...

AI Technical Summary

Problems solved by technology

Piezoelectric sensing technology is based on piezoelectric elements and active Lamb technology to realize structural health monitoring, but for pipelines with complex structures, a large number of Lamb wave reflection signals will be generated during measurement, and the superposition of these reflection signals will lead to serious mode aliasing , so that the cracks cannot be accurately identified, which directly affects the monitoring effect

Acoustic emission technology is only suitable for monitoring cracks that are cracking or expanding. When the structure has large-scale defects in areas with less stress, it will lead to missed inspections

Fiber Bragg grating sensors based on fiber optic sensing technology are limited by the bandwidth of incident light, and fiber Bragg grating sensors have fewer measuring points. In the field of distributed multi-point detection, it is difficult to achieve fully distributed online health monitoring of structures, and may lead to missed detection

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