{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,15]],"date-time":"2026-02-15T03:22:17Z","timestamp":1771125737301,"version":"3.50.1"},"reference-count":25,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2014,10,22]],"date-time":"2014-10-22T00:00:00Z","timestamp":1413936000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The electromagnetic acoustic transducer (EMAT), a non-contact NDT tool with large lift-off, is becoming an attractive method for detecting the cracks in the metal parts. However, the lift-off of the transducer has a direct effect on the feature that is used to characterize the defects. A detailed investigation on the relationship between the feature and the lift-off of the EMAT is crucial in the detection process. This paper investigates the lift-off effect on the feature, cut-off frequency of EMAT in the Rayleigh wave. The study can be divided into two parts. Firstly, with a multi-field coupling environment, 2-D electromagnetic and wave generation EMAT models are built to simulate the interaction of the Rayleigh wave with the surface crack. Then, the lift-off effect on the cut-off frequency is investigated through simulation and experiment. Compared to the previous studies, it is found that lift-off would cause a negative result when the lift-off varies in the testing process. Besides, the calibration obtained from the tests at a random lift-off value can be used in other tests with any different lift off value provided that the lift-off is kept as a constant during the detection process.<\/jats:p>","DOI":"10.3390\/s141019687","type":"journal-article","created":{"date-parts":[[2014,10,22]],"date-time":"2014-10-22T11:01:56Z","timestamp":1413975716000},"page":"19687-19699","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":18,"title":["Influence of the Lift-Off Effect on the Cut-Off Frequency of the EMAT-Generated Rayleigh Wave Signal"],"prefix":"10.3390","volume":"14","author":[{"given":"Pengxing","family":"Yi","sequence":"first","affiliation":[{"name":"School of Mechanical Science & Engineering, Huazhong University of Science & Technology, Wuhan 430074, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kang","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Mechanical Science & Engineering, Huazhong University of Science & Technology, Wuhan 430074, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yahui","family":"Li","sequence":"additional","affiliation":[{"name":"School of Mechanical Science & Engineering, Huazhong University of Science & Technology, Wuhan 430074, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4332-071X","authenticated-orcid":false,"given":"Xuming","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Life Science & Technology, Huazhong University of Science & Technology,  Wuhan 430074, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2014,10,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"5996","DOI":"10.3390\/s130505996","article-title":"Air-coupled piezoelectric transducers with active polypropylene foam matching layers","volume":"13","year":"2013","journal-title":"Sensors"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3458","DOI":"10.3390\/s140203458","article-title":"A New Omni-Directional EMAT for Ultrasonic Lamb Wave Tomography Imaging of Metallic Plate Defects","volume":"14","author":"Huang","year":"2014","journal-title":"Sensors"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"171","DOI":"10.1016\/j.ndteint.2009.10.009","article-title":"Initial tests for designing a high temperature EMAT with pulsed electromagnet","volume":"43","author":"Dixon","year":"2010","journal-title":"NDT E Int."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1016\/j.sna.2012.06.014","article-title":"Research on the lift-off effect of generating longitudinal guided waves in pipes based on magnetostrictive effect","volume":"184","author":"Xu","year":"2012","journal-title":"Sens. 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