Scour Monitoring System for Subsea Pipeline Based on Active Thermometry: Numerical and Experimental Studies

Abstract

A scour monitoring system for subsea pipeline based on active thermometry is proposed in this paper. The temperature reading of the proposed system is based on a distributed Brillouin optical fiber sensing technique. A thermal cable acts as the main component of the system, which consists of a heating belt, armored optical fibers and heat-shrinkable tubes which run parallel to the pipeline. The scour-induced free span can be monitored through different heat transfer behaviors of in-water and in-sediment scenarios during heating and cooling processes. Two sets of experiments, including exposing different lengths of the upper surface of the pipeline to water and creating free spans of various lengths, were carried out in laboratory. In both cases, the scour condition was immediately detected by the proposed monitoring system, which confirmed the system is robust and very sensitive. Numerical study of the method was also investigated by using the finite element method (FEM) with ANSYS, resulting in reasonable agreement with the test data. This brand new system provides a promising, low cost, highly precise and flexible approach for scour monitoring of subsea pipelines.

Monitoring Concrete Deterioration Due to Reinforcement Corrosion by Integrating Acoustic Emission and FBG Strain Measurements

“…Fiber optic sensors carry numerous advantages over traditional sensors, such as small size, immunity to electromagnetic interference, corrosion resistance, and real-time monitoring [20,21]. Therefore, they are very suitable for corrosion monitoring in reinforced concrete structures.…”

Feasibility Study of Real-Time Monitoring of Pin Connection Wear Using Acoustic Emission

“…Therefore, an effective nondestructive method for monitoring the health of pin connections in real time is necessary. With the recent advances in structural health monitoring (SHM) [2][3][4][5][6][7][8] and nondestructive evaluation (NDE) [9,10], many monitoring and evaluation methods, such as modal characteristics-based methods [11][12][13], active sensing [14][15][16][17][18][19][20], electromechanical impedance [21][22][23][24][25], ultrasonic guided wave [26], active thermography [26][27][28] and vibrothermography [29,30], among others, are available. Among them, acoustic emission technique [31][32][33][34][35][36][37] is an effective nondestructive technique that can characterize the wear process [38,39], and it has been widely used in civil engineering [40][41][42][43], mechanical engineering [44][45]…”

Distributed Deformation Monitoring for a Single-Cell Box Girder Based on Distributed Long-Gage Fiber Bragg Grating Sensors

“…In recent years, many in-service bridges have installed structural health monitoring systems based on FBG sensors to observe the long-term strain–stress variation and vibration [ 20 , 21 , 22 ], and monitor bridge scour [ 23 ]. Similar FBG-based applications are reported in strain monitoring [ 24 , 25 , 26 ] for leakages in pipelines, scour monitoring [ 27 ], and concrete deterioration and reinforcement corrosion [ 28 , 29 , 30 ]. A long-gage fiber Bragg grating (LFBG) strain sensor is especially suitable for practical strain monitoring because it allows for the entire structure to be covered by a limited number of sensors.…”