{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,14]],"date-time":"2025-11-14T17:23:26Z","timestamp":1763141006687,"version":"build-2065373602"},"reference-count":14,"publisher":"MDPI AG","issue":"12","license":[{"start":{"date-parts":[[2017,11,24]],"date-time":"2017-11-24T00:00:00Z","timestamp":1511481600000},"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>Due to the symmetry of conventional periodic-permanent-magnet electromagnetic acoustic transducers (PPM EMATs), two shear (SH) waves can be generated and propagated simultaneously in opposite directions, which makes the signal recognition and interpretation complicatedly. Thus, this work presents a new SH wave PPM EMAT design, rotating the parallel line sources to realize the wave beam focusing in a single-direction. The theoretical model of distributed line sources was deduced firstly, and the effects of some parameters, such as the inner coil width, adjacent line sources spacing and the angle between parallel line sources, on SH wave focusing and directivity were studied mainly with the help of 3D FEM. Employing the proposed PPM EMATs, some experiments are carried out to verify the reliability of FEM simulation. The results indicate that rotating the parallel line sources can strength the wave on the closing side of line sources, decreasing the inner coil width and the adjacent line sources spacing can improve the amplitude and directivity of signals excited by transducers. Compared with traditional PPM EMATs, both the capacity of unidirectional excitation and directivity of the proposed PPM EMATs are improved significantly.<\/jats:p>","DOI":"10.3390\/s17122722","type":"journal-article","created":{"date-parts":[[2017,11,24]],"date-time":"2017-11-24T06:39:25Z","timestamp":1511505565000},"page":"2722","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":31,"title":["Optimization of a Focusable and Rotatable Shear-Wave Periodic Permanent Magnet Electromagnetic Acoustic Transducers for Plates Inspection"],"prefix":"10.3390","volume":"17","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8339-4441","authenticated-orcid":false,"given":"Xiaochun","family":"Song","sequence":"first","affiliation":[{"name":"School of Mechanical Engineering, Hubei University of Technology, Wuhan 430068, China"}]},{"given":"Gongzhe","family":"Qiu","sequence":"additional","affiliation":[{"name":"School of Mechanical Engineering, Hubei University of Technology, Wuhan 430068, China"}]}],"member":"1968","published-online":{"date-parts":[[2017,11,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.ndteint.2017.02.005","article-title":"Multi-coil focused EMAT for characterization of surface-breaking defects of arbitrary orientation","volume":"88","author":"Thring","year":"2017","journal-title":"NDT E Int."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"3471","DOI":"10.3390\/s150203471","article-title":"Enhancement of the excitation efficiency of a torsional wave PPM EMAT array for pipe inspection by optimizing the element number of the array based on 3-D FEM","volume":"15","author":"Wang","year":"2015","journal-title":"Sensors"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Huang, S., Zhang, Y., Wang, S., and Zhao, W. (2016). Multi-Mode Electromagnetic Ultrasonic Lamb Wave Tomography Imaging for Variable-Depth Defects in Metal Plates. Sensors, 16.","DOI":"10.3390\/s16050628"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1016\/j.ndteint.2016.11.010","article-title":"Circumferential guided wave EMAT system for pipeline screening using shear horizontal ultrasound","volume":"86","author":"Clougha","year":"2017","journal-title":"NDT E Int."},{"key":"ref_5","first-page":"1","article-title":"Beam-focused shear-horizontal wave generation in a plate by a circular magnetostrictive patch transducer employing a planar solenoid array","volume":"18","author":"Lee","year":"2009","journal-title":"Smart Mater. Strut."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"12","DOI":"10.3901\/JME.2016.06.012","article-title":"Review of modeling method and optimum design of EMAT transmitters based on Lorentz principle","volume":"52","author":"Feiran","year":"2016","journal-title":"J. Mech. Eng."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"137","DOI":"10.1016\/j.ndteint.2013.12.009","article-title":"Frequency dependent directivity of periodic permanent magnet electromagneitc acoustic transducers","volume":"62","author":"Hill","year":"2014","journal-title":"NDT E Int."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/B978-0-12-477919-8.50010-8","article-title":"Physical principles of measurements with EMAT transducers","volume":"19","author":"Thompson","year":"1990","journal-title":"Phys. Acoust."},{"key":"ref_9","first-page":"1166","article-title":"Evaluating EMAT designs for selected applications","volume":"45","author":"Maxfield","year":"1987","journal-title":"Mater. 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Actuators A"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"30","DOI":"10.1016\/j.ndteint.2012.04.001","article-title":"On the use of absorbing layers to simulate the propagation of elastic waves in unbounded isotropic media using commercially available finite element packages","volume":"51","author":"Rajagopal","year":"2012","journal-title":"NDT E Int."},{"key":"ref_14","unstructured":"Ribichini, R. (2011). Modeling of Electronmagnetic Acoustic Transducers. [Ph.D. Thesis, Imperial College London]."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/12\/2722\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T18:51:09Z","timestamp":1760208669000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/17\/12\/2722"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2017,11,24]]},"references-count":14,"journal-issue":{"issue":"12","published-online":{"date-parts":[[2017,12]]}},"alternative-id":["s17122722"],"URL":"https:\/\/doi.org\/10.3390\/s17122722","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2017,11,24]]}}}