Journal ArticleDOI
An SH-wave EMAT technique for gas pipeline inspection
Masahiko Hirao,Hirotsugu Ogi +1 more
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TLDR
In this paper, a periodic-permanent-magnet (PPM) EMAT is placed inside the pipe, which generates and receives the SH guided waves traveling in the circumferential direction with the axial polarization.Abstract:
An EMAT technique has been developed to detect corrosion defects on the outer surfaces of steel pipelines. A periodic-permanent-magnet (PPM) EMAT is placed inside the pipe, which generates and receives the SH guided waves traveling in the circumferential direction with the axial polarization. Wheels installed on the PPM-EMAT facilitate the linear movement in the axial direction and are useful for a quick inspection. At each point in scanning, the amplitude and phase shift of the round-trip signals in the SH0 and SH1 modes are measured using a superheterodyne phase-sensitive detector. They respond uniquely to surface defects and provide relevant information for locating axial positions of defects and evaluating the depth. The amplitude and phase shift of the SH1 mode are more sensitive to the presence of the defects than those of the SH0 mode. This technique is useful even if the protective resin coating is tightly glued on the pipes and lowered the signal intensity.read more
Citations
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Journal ArticleDOI
Integrity evaluation of steel products using EMATs
TL;DR: In this article, a spiral EMAT was used to generate shear waves to detect internal and surface defects in steel samples at one inspection using electro-magnetic acoustic transducers (EMATs).
Journal ArticleDOI
평판 구조물의 영상화를 위한 위상 배열 시스템 개발 및 응용
TL;DR: An ultrasonic magnetostrictive transducer-based phased array system for imaging defects in plate structures is newly proposed in this article, which consists of a multi-channel function generator, power amplifiers, preamplifiers and a data acquisition unit.
Journal ArticleDOI
Characteristic analysis of electromagnetic acoustic transducers for helical shear horizontal wave based on magnetostrictive effect.
TL;DR: In this paper, a transducer with a sector configuration is designed for generating helical shear horizontal waves in a pipeline, and the model is built in the finite element simulation software of COMSOL multiphysics.
Journal ArticleDOI
Planar Hall sensor for quantitative measurement of pipe wall thickness reduction based on the magnetic flux density method
Hong-Quang Pham,Trung-Kien Nguyen,Trung-Kien Nguyen,Quang-Ngan Pham,Van-Sy Le,Minh-Hung Vu,Thi-Thuy Truong,Van-Tai Nguyen,Azzedine Bousseksou,S. Wane,Ferial Terki,Quang-Hung Tran +11 more
TL;DR: In this paper, the authors verify the effectiveness of magnetic flux density method in quantitatively monitoring thickness reduction through simulation and experimental verification, and show that the proportion of magnetic signal change is 1.4 mT per 10% wall loss.
Journal ArticleDOI
Transverse Crack Detection of Rail Base Considering Wedge-Like Structure and Using a Bulk-Wave Electromagnetic Acoustic Transducer
TL;DR: In this paper , the authors further study and verify a bulk-wave electromagnetic acoustic transducer (EMAT) for the transverse crack detection of rail base and propose an auxiliary method for achieving efficient detection.
References
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Journal ArticleDOI
Review of progress in quantitative NDE: Williamsburg, VA, USA, 21–26 June 1987
Book ChapterDOI
2 – Guided Wave Propagation in Elongated Cylinders and Plates
T.R. Meeker,A.H. Meitzler +1 more
Journal ArticleDOI
Field dependence of coupling efficiency between electromagnetic field and ultrasonic bulk waves
TL;DR: In this paper, the magnetic-field dependence of the wave amplitudes was studied by examining the magnetic field dependence of a spiral elongated coil placed on a thin plate of low carbon steel, which receives the longitudinal and the shear waves propagating in the thickness direction in the presence of bias magnetic field.