A new electromagnetic acoustic transducer design for generating torsional guided wave modes for pipe inspections
Samuel Hill,Steve Dixon,K Sri Harsha Reddy,Prabhu Rajagopal,Krishnan Balasubramaniam +4 more
- Vol. 1806, Iss: 1, pp 050003
TLDR
In this paper, a new design of Electromagnetic Acoustic Transducer (EMAT) that can generate a T(0, 1) as a single transducer, rat...Abstract:
Guided waves inspection is a well-established method for the long-range ultrasonic inspection of pipes. Guided waves, used in a pulse-echo arrangement, can inspect a large range of the pipe from a single point as the pipe structure carries the waves over a large distance due to the relatively low attenuation of the wave modes. However, the complexity of the dispersion characteristics of these pipe guided wave modes are well known, and can lead to diffculty interpreting the obtained results. The torsional family of guided wave modes are generally considered to have much simpler dispersion characteristics; especially the fundamental T(0,1) mode, which is nominally non-dispersive, making it particularly useful for guided wave inspection. Torsional waves have been generated by a circumferential ring of transducers to approximate an axi-symmetric load to excite this T(0, 1) mode. Presented here is a new design of Electromagnetic Acoustic Transducer (EMAT) that can generate a T(0, 1) as a single transducer, rat...read more
Citations
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Shear horizontal wave transducers for structural health monitoring and nondestructive testing: A review.
Hongchen Miao,Faxin Li +1 more
TL;DR: In this paper, a review of the state-of-the-art SH wave transducers for structural health monitoring (SHM) and nondestructive testing (NDT) is presented.
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Development of ultrasonic guided wave inspection methodology for steam generator tubes of prototype fast breeder reactor.
TL;DR: The thermal expansion bend of an SG tube shows that the bend does not have much influence on the mode and the multiple circumferential defects considered in the bend are detected with good sensitivity and excellent correlation between finite element simulation and experimental results.
Journal ArticleDOI
Unidirectional Shear Horizontal Wave Generation With Side-Shifted Periodic Permanent Magnets Electromagnetic Acoustic Transducer
TL;DR: A unidirectional SH EMAT consisting of two racetrack coils and two interlaced PPM arrays, that are slightly shifted sideways, in such a way that the generated wavefronts still properly interfere.
Journal ArticleDOI
An Ultrasonic Guided Wave Mode Selection and Excitation Method in Rail Defect Detection
TL;DR: In this article, a novel guided wave mode selection and excitation method is proposed, which is effective for detection and positioning of the three parts of rail defects using ultrasonic guided wave.
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Development of a Helical Lamb Wave Electromagnetic Acoustic Transducer for Pipeline Inspection
TL;DR: Based on the Lorentz mechanism, the developed transducer contains the fan-shaped magnetic poles and a two-layer coil, which can generate wave with diverse incident angle as discussed by the authors.
References
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Journal ArticleDOI
Time-frequency distributions-a review
TL;DR: A review and tutorial of the fundamental ideas and methods of joint time-frequency distributions is presented with emphasis on the diversity of concepts and motivations that have gone into the formation of the field.
Journal ArticleDOI
Three‐Dimensional Investigation of the Propagation of Waves in Hollow Circular Cylinders. I. Analytical Foundation
TL;DR: In this paper, the propagation of free harmonic waves along a hollow circular cylinder of infinite extent is discussed within the framework of the linear theory of elasticity, and a characteristic equation appropriate to the circular hollow cylinder is obtained by use of the Helmholtz potentials for arbitrary values of the physical parameters involved.
Journal ArticleDOI
The reflection of the fundamental torsional mode from cracks and notches in pipes
TL;DR: A quantitative study of the reflection of the T(0,1) mode from defects in pipes in the frequency range 10-300 kHz has been carried out, finite element predictions being validated by experiments on selected cases.
Journal ArticleDOI
The excitation of Lamb waves in pipes using dry-coupled piezoelectric transducers
D. N. Alleyne,Peter Cawley +1 more
TL;DR: In this article, the development of a dry-coupled piezoelectric transducer system for the detection of corrosion in chemical plant pipework using cylindrical Lamb waves is described.
Journal ArticleDOI
An SH-wave EMAT technique for gas pipeline inspection
Masahiko Hirao,Hirotsugu Ogi +1 more
TL;DR: 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.