Underwater Pipeline Inspection Using Guided Waves

Abstract

Underwater pipeline inspections are conducted using ultrasonic cylindrical guided waves in the laboratory environment. Three different types of mechanical defects—gouge, removed metal, and dent—are fabricated in small-diameter, 22.22-mm, aluminum pipes and tested. To efficiently propagate the antisymmetric (flexural) cylindrical guided waves through the aluminum pipe in water, a new transducer holder device is designed. The device uses commercially available ultrasonic transducers that generate compressional ultrasonic waves in the water. The device can change the striking angle of the incident beam from 0 to 51 deg. With the help of this device, the incident angle adjustment and frequency sweeping can be carried out. This is necessary for obtaining the time history of the received signals for various incident angles and signal frequencies; then these time histories are converted to Vf curves, or received signal amplitude versus frequency curves. From the amplitude of these Vf curves, the type and extent of the mechanical defects can be estimated. This investigation shows that the new coupler device can be effectively used for health monitoring of underwater pipelines using guided waves.

Guided Waves for Nondestructive Testing – Experiment and Analysis

“…The transmitter-receiver pair then scans the surface of the specimen to generate the acoustic image of the interface [ 16 ] . The Lamb wave inspection technique has been also used to inspect large metal plates [ 17,18 ] , metal pipes [19][20][21] , concrete beams [ 22,23 ] and reinforcing bars in concrete [ 24,25 ] .…”

Simplified Ultrasonic Damage Detection in Fluid-Filled Pipes

“…However as opposed to these leak studies, partial damage detection-i.e. without pipe cracks and leaks-in fluid-filled immersed pipes using guided waves have only been reported in a limited number of works [21,22]. Aristégui et al [17] investigate guided wave propagation in pipes with liquid loading on both the inside and outside of the pipe.…”

“…Na and Kundu [21] used flexural guided waves for the detection of material removal from the outer wall of a 0.6 m long water-filled pipe submerged in water. Djili et al [22] used a single transducer for the emission and reception leakyguided waves to detect and locate small notches on the outer surface of a filled tube immersed in water.…”

Water Level Sensing in a Steel Vessel Using A0 and Quasi-Scholte Waves

“…Bingham et al [6] used ultrasonic guided waves to identify the mass loading on ship hulls. Na and Kundu [7] detected gouges and dents in an underwater pipeline using guided waves. Chen et al [8] developed a damage identification approach using the A 0 mode for evaluating corrosion damage in submerged structures.…”