scholarly journals Mode control of guided wave in magnetic hollow cylinder using electromagnetic acoustic transducer array

2015 ◽  
Vol 47 (2) ◽  
pp. 196-203 ◽  
Author(s):  
Akinori Furusawa ◽  
Fumio Kojima ◽  
Atsushi Morikawa
Keyword(s):  
Hollow Cylinder ◽  
Guided Wave ◽  
Electromagnetic Acoustic Transducer ◽  
Transducer Array ◽  
Mode Control ◽  
Acoustic Transducer

scholarly journals High Temperature Shear Horizontal Electromagnetic Acoustic Transducer for Guided Wave Inspection

Sensors ◽  
2016 ◽  
Vol 16 (4) ◽  
pp. 582 ◽  
Author(s):  
Maria Kogia ◽  
Tat-Hean Gan ◽  
Wamadeva Balachandran ◽  
Makis Livadas ◽  
Vassilios Kappatos ◽  
...  
Keyword(s):  
High Temperature ◽  
Guided Wave ◽  
Electromagnetic Acoustic Transducer ◽  
Acoustic Transducer ◽  
Temperature Shear ◽  
Shear Horizontal

An improved design of shear horizontal guided wave electromagnetic acoustic transducer

2020 ◽  
Vol 62 (8) ◽  
pp. 494-497
Author(s):  
Xu Zhang ◽  
Sheng Feng ◽  
Jun Tu ◽  
Xiaochun Song
Keyword(s):  
Guided Waves ◽  
Cost Effective ◽  
Guided Wave ◽  
Experimental Investigations ◽  
Electromagnetic Acoustic Transducer ◽  
Rectangular Array ◽  
Acoustic Transducers ◽  
Acoustic Transducer ◽  
Improved Design ◽  
Shear Horizontal

This work proposes the use of a Halbach magnet structure to enhance the generation efficiency of shear horizontal (SH) guided waves on a plate. SH waves are normally generated using periodic permanent magnet (PPM) electromagnetic acoustic transducers (EMATs). Two PPM configurations are designed using a Halbach magnet array and the enhancements of the static magnetic fields of the two magnet arrays are validated by the finite element method, indicating that these configurations can increase the peak flux density compared with the conventional configuration. Numerical analysis and experimental investigations indicate that a racetrack coil combined with either a rectangular or triangular Halbach magnet array can enhance the amplitude of the SH guided wave by factors of ∼1.2 and ∼1.1, respectively, and that the rectangular array performs better and is more cost effective.

scholarly journals Simulation of an Electromagnetic Acoustic Transducer Array by Using Analytical Method and FDTD

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Yuedong Xie ◽  
Sergio Rodriguez ◽  
Wenbo Zhang ◽  
Zenghua Liu ◽  
Wuliang Yin
Keyword(s):  
Analytical Solution ◽  
Time Domain ◽  
Fdtd Method ◽  
Force Density ◽  
Large Radius ◽  
Electromagnetic Acoustic Transducer ◽  
Transducer Array ◽  
Ultrasound Waves ◽  
Acoustic Transducer ◽  
Frequency Regime

Previously, we developed a method based on FEM and FDTD for the study of an Electromagnetic Acoustic Transducer Array (EMAT). This paper presents a new analytical solution to the eddy current problem for the meander coil used in an EMAT, which is adapted from the classic Deeds and Dodd solution originally intended for circular coils. The analytical solution resulting from this novel adaptation exploits the large radius extrapolation and shows several advantages over the finite element method (FEM), especially in the higher frequency regime. The calculated Lorentz force density from the analytical EM solver is then coupled to the ultrasonic simulations, which exploit the finite-difference time-domain (FDTD) method to describe the propagation of ultrasound waves, in particular for Rayleigh waves. Radiation pattern obtained with Hilbert transform on time-domain waveforms is proposed to characterise the sensor in terms of its beam directivity and field distribution along the steering angle, which can produce performance parameters for an EMAT array, facilitating the optimum design of such sensors.

scholarly journals Nondestructive Inspection of Corrosion and Delamination at the Concrete-Steel Reinforcement Interface

2002 ◽  
Author(s):  
Tri Miller ◽  
Christopher J. Hauser ◽  
Tribikram Kundu
Keyword(s):  
Guided Waves ◽  
Guided Wave ◽  
Ultrasonic Guided Waves ◽  
Reinforcing Steel ◽  
Electromagnetic Acoustic Transducer ◽  
Long Distance ◽  
Steel Bar ◽  
Acoustic Transducer ◽  
Steel Bars ◽  
Aging Infrastructure

This paper explores the feasibility of detecting and quantifying corrosion and delamination at the interface between reinforcing steel bar and concrete using ultrasonic guided waves. The problem of corrosion and delamination of the reinforcing steel in the aging infrastructure has increased significantly in the last three decades and is likely to keep on increasing. Ultrasonic cylindrical guided waves that can propagate a long distance along the reinforcing steel bar are found to be sensitive to the interface conditions between steel bar and concrete. Ultrasonic transducers are used to launch and detect cylindrical guided waves along the steel bar. The traditional ultrasonic testing methods, for instance the pulse-echo method, where reflection, transmission, and scattering of longitudinal waves are used for detecting large voids in concrete, are not very efficient for detecting corrosion and delamination at the interface between concrete and steel bar. For this study four sets of specimens were prepared. They are rebars and plain steel bars with corrosion and physical separation. Transducers used during the experiment are the Electromagnetic Acoustic Transducer (EMAT) and the Piezoelectric Transducer (PZT). The experiment suggests that the guided wave inspection technique is feasible for the health monitoring of reinforced concrete structures. It also reveals that the ultrasonic guided waves are sensitive to the type of steel used and to the rib patterns on the reformed steel bars.

scholarly journals Characteristics of T(0, 1) Guided-Wave Point-Focusing Electromagnetic Acoustic Transducer for Pipe Inspection

2020 ◽  
Vol 20 (6) ◽  
pp. 2895-2903 ◽  
Author(s):  
Songling Huang ◽  
Hongyu Sun ◽  
Gongtian Shen ◽  
Baoxuan Wang ◽  
Qing Wang ◽  
...  
Keyword(s):  
Guided Wave ◽  
Pipe Inspection ◽  
Electromagnetic Acoustic Transducer ◽  
Acoustic Transducer

scholarly journals A new electromagnetic acoustic transducer design for generating torsional guided wave modes for pipe inspections

2017 ◽  
Author(s):  
Samuel Hill ◽  
Steve Dixon ◽  
Sri Harsha Reddy K. ◽  
Prabhu Rajagopal ◽  
Krishnan Balasubramaniam
Keyword(s):  
Guided Wave ◽  
Electromagnetic Acoustic Transducer ◽  
Acoustic Transducer ◽  
Transducer Design ◽  
Wave Modes
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