A circumferential SH wave piezoelectric transducer array for damage detection in large-diameter pipes

Abstract

Torsional or longitudinal wave-based inspection is an effective method for rapid defect screening in pipes, but it has difficulty to locate the circumferential position of a defect due to the axially symmetric properties of torsional and longitudinal modes. In order to overcome this problem, several flexural-wave-based focusing methods have been proposed while multiple mode propagation associated with dispersion has to be taken into account in them, which increases the complexity of identifying defects in practical applications. In this work, based on our recently developed bidirectional SH wave piezoelectric transducer (BSH-PT), a fundamental circumferential shear horizontal (CSH0) wave linear phased array was proposed for in-situ defect localization in large-diameter pipes. Firstly, the working principle of the BSH-PT array was presented and its performance on defects detection was assessed by simulations using the total focusing method (TFM). Then, experiments were conducted to examine the array’s performance. Results showed that the proposed BSH-PT array can detect multiple defects simultaneously at varied frequencies. Finally, a method for eliminating the mirrored artifact was proposed and then validated by both simulations and experiments on pipes. Considering the quasi-nondispersive character of CSH0 wave and the desirable performance of the BSH-PT on exciting and receiving pure CSH0 wave, the proposed CSH0 wave phased array may be useful in structural health monitoring (SHM) of large-diameter pipes such as pressure vessels and oil tanks.

Sleeved waveguide ultrasonic sensor for monitoring concrete health

“…This has increased interest and attention in ultrasonic guided waves for NDT applications and intelligent health monitoring of structures. 4 With proper mode and frequency selection, guided wave ultrasonics have been harnessed for inspection of pipelines, [5][6][7] annular tank plates, [8][9][10][11][12][13] rods, 14,15 railways [16][17][18] and aircraft. [19][20][21] Several studies have been conducted on guided ultrasonic wave techniques for health monitoring and damage detection in concrete structures.…”

“…With proper mode and frequency selection, guided wave ultrasonics have been harnessed for inspection of pipelines, 5–7 annular tank plates, 8–13 rods, 14,15 railways 16–18 and aircraft. 19–21 Several studies have been conducted on guided ultrasonic wave techniques for health monitoring and damage detection in concrete structures.…”