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Variational mode decomposition linked wavelet method for EMAT denoise with large lift-off effect

Lookup NU author(s): Professor Gui Yun TianORCiD



This is the authors' accepted manuscript of an article that has been published in its final definitive form by Elsevier Ltd, 2019.

For re-use rights please refer to the publisher's terms and conditions.


© 2019 Elsevier LtdElectromagnetic acoustic transducer (EMAT) is an emerging non-destructive testing technique which is widely used in the industry. EMAT has advantages of a non-coupling agent with the capability of big lift-off detection. However, EMAT has an issue of low efficiency in conversion and it is susceptible to noise. This paper proposes a modified variational mode decomposition (VMD) linked wavelet method for EMAT denoising. It enables to suppress both high-frequency narrowband noise and normal noise in EMAT signals with a large lift-off detection condition. In particular, a new ultrasonic echo signal model with a large lift-off influence is proposed for interpretation of denoising mechanism. To investigate the efficacy and the robustness of the proposed method, experimental studies have been carried out for different test samples. A comparative analysis has been undertaken to confirm that the proposed method not only removes the noise but also preserves the information of defect. The Matlab demo code can be linked:

Publication metadata

Author(s): Si D, Gao B, Guo W, Yan Y, Tian GY, Yin Y

Publication type: Article

Publication status: Published

Journal: NDT & E International

Year: 2019

Volume: 107

Online publication date: 26/07/2019

Acceptance date: 21/07/2019

Date deposited: 09/10/2019

ISSN (print): 0963-8695

ISSN (electronic): 1879-1174

Publisher: Elsevier Ltd


DOI: 10.1016/j.ndteint.2019.102149


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