EurekaMag.com logo
+ Site Statistics
References:
53,869,633
Abstracts:
29,686,251
+ Search Articles
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on LinkedInFollow on LinkedIn

+ Translate

Multi-Mode Electromagnetic Ultrasonic Lamb Wave Tomography Imaging for Variable-Depth Defects in Metal Plates



Multi-Mode Electromagnetic Ultrasonic Lamb Wave Tomography Imaging for Variable-Depth Defects in Metal Plates



Sensors 16(5): -



This paper proposes a new cross-hole tomography imaging (CTI) method for variable-depth defects in metal plates based on multi-mode electromagnetic ultrasonic Lamb waves (LWs). The dispersion characteristics determine that different modes of LWs are sensitive to different thicknesses of metal plates. In this work, the sensitivities to thickness variation of A0- and S0-mode LWs are theoretically studied. The principles and procedures for the cooperation of A0- and S0-mode LW CTI are proposed. Moreover, the experimental LW imaging system on an aluminum plate with a variable-depth defect is set up, based on A0- and S0-mode EMAT (electromagnetic acoustic transducer) arrays. For comparison, the traditional single-mode LW CTI method is used in the same experimental platform. The imaging results show that the computed thickness distribution by the proposed multi-mode method more accurately reflects the actual thickness variation of the defect, while neither the S0 nor the A0 single-mode method was able to distinguish thickness variation in the defect region. Moreover, the quantification of the defect's thickness variation is more accurate with the multi-mode method. Therefore, theoretical and practical results prove that the variable-depth defect in metal plates can be successfully quantified and visualized by the proposed multi-mode electromagnetic ultrasonic LW CTI method.

(PDF emailed within 0-6 h: $19.90)

Accession: 058354360

Download citation: RISBibTeXText

PMID: 27144571

DOI: 10.3390/s16050628



Related references

A new omni-directional EMAT for ultrasonic Lamb wave tomography imaging of metallic plate defects. Sensors 14(2): 3458-3476, 2014

Multi-mode Lamb wave tomography with arrival time sorting. Journal of the Acoustical Society of America 117(4 Pt 1): 2028-2038, 2005

Guided lamb waves and L-SAFT processing technique for enhanced detection and imaging of corrosion defects in plates with small depth-to-wavelength ratio. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 51(10): 1287-1297, 2004

Driving mechanism on magnetostrictive type electromagnetic acoustic transducer for symmetrical vertical-mode Lamb wave and for shear horizontal-mode plate wave. Ultrasonics 34(7): 729-736, 1996

Development of an ultrasonic inspection robot using an electromagnetic acoustic transducer for a Lamb wave and an SH-plate wave. Ultrasonics 42(1-9): 825-829, 2004

Elastic constants measurement of anisotropic Olivier wood plates using air-coupled transducers generated Lamb wave and ultrasonic bulk wave. Ultrasonics 50(4-5): 502-507, 2010

Non-contact ultrasonic technique for Lamb wave characterization in composite plates. Ultrasonics 64: 162-169, 2015

Ultrasonic Lamb wave tomography. Inverse Problems 18(6): 1795-1808, 2002

Design of mode selective actuators for Lamb wave excitation in composite plates. CEAS Aeronautical Journal 4(1): 105-112, 2013

Minimizing influence of multi-modes and dispersion of electromagnetic ultrasonic lamb waves. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control 57(12): 2725-2733, 2010

Ultrasonic Lamb wave diffraction tomography. Ultrasonics 39(4): 269-281, 2001

Lamb Wave Multi-touch Ultrasonic Touchscreen. IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2017

Importance of the near Lamb mode imaging of multilayered composite plates. Ultrasonics 39(4): 283-290, 2001

Lift-off compensation for improved accuracy in ultrasonic lamb wave velocity measurements using electromagnetic acoustic transducers (EMATs). Ultrasonics 44 Suppl 1: E1401-4, 2006

The propagation in metal tubing of ultrasonic wave modes equivalent to Lamb waves. Ultrasonics 17(1): 11-19, 1979