{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,16]],"date-time":"2026-04-16T16:29:14Z","timestamp":1776356954810,"version":"3.51.2"},"reference-count":27,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2022,2,9]],"date-time":"2022-02-09T00:00:00Z","timestamp":1644364800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["51807052"],"award-info":[{"award-number":["51807052"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["51707058"],"award-info":[{"award-number":["51707058"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Hubei Natural Science Foundation Innovation Group Project","award":["2019CFA021"],"award-info":[{"award-number":["2019CFA021"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>An electromagnetic acoustic transducer (EMAT) is suitable for measuring the propagation time more accurately without causing abrasion to the transducer during testing due to the principle of its excitation. This work designs a flux-concentrating EMAT with a radial-flux-focusing permanent magnet to significantly enhance static magnetic field strength. Through theoretical analysis and finite element simulation, two kinds of coils are designed according to the concentration areas of the horizontal and vertical components of the magnetic field. One is used to generate pure longitudinal waves, and the other is used to generate both longitudinal waves and shear waves. The experimental comparison shows that the amplitudes of the pure longitudinal wave and the dual-mode wave excited by the two kinds of coils with the radial-flux-focusing magnet are more than two times higher than those with the ordinary magnet. Therefore, the flux-concentrating EMAT with the appropriate coil provides an insight into realizing more accurate detection where longitudinal wave detection is required.<\/jats:p>","DOI":"10.3390\/s22041316","type":"journal-article","created":{"date-parts":[[2022,2,9]],"date-time":"2022-02-09T21:26:48Z","timestamp":1644442008000},"page":"1316","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["A New Design of the Dual-Mode and Pure Longitudinal EMAT by Using a Radial-Flux-Focusing Magnet"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9197-5716","authenticated-orcid":false,"given":"Xu","family":"Zhang","sequence":"first","affiliation":[{"name":"Hubei Key Laboratory of Modern Manufacturing Quantity Engineering, School of Mechanical Engineering, Hubei University of Technology, Wuhan 430068, China"}]},{"given":"Weiwen","family":"Li","sequence":"additional","affiliation":[{"name":"Hubei Key Laboratory of Modern Manufacturing Quantity Engineering, School of Mechanical Engineering, Hubei University of Technology, Wuhan 430068, China"}]},{"given":"Bo","family":"Li","sequence":"additional","affiliation":[{"name":"Hubei Key Laboratory of Modern Manufacturing Quantity Engineering, School of Mechanical Engineering, Hubei University of Technology, Wuhan 430068, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4974-9077","authenticated-orcid":false,"given":"Jun","family":"Tu","sequence":"additional","affiliation":[{"name":"Hubei Key Laboratory of Modern Manufacturing Quantity Engineering, School of Mechanical Engineering, Hubei University of Technology, Wuhan 430068, China"}]},{"given":"Chunhui","family":"Liao","sequence":"additional","affiliation":[{"name":"Hubei Key Laboratory of Modern Manufacturing Quantity Engineering, School of Mechanical Engineering, Hubei University of Technology, Wuhan 430068, China"}]},{"given":"Qiao","family":"Wu","sequence":"additional","affiliation":[{"name":"Hubei Key Laboratory of Modern Manufacturing Quantity Engineering, School of Mechanical Engineering, Hubei University of Technology, Wuhan 430068, China"}]},{"given":"Sheng","family":"Feng","sequence":"additional","affiliation":[{"name":"Xianning Institute of Information and Standardization, Xianning 437000, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8339-4441","authenticated-orcid":false,"given":"Xiaochun","family":"Song","sequence":"additional","affiliation":[{"name":"Hubei Key Laboratory of Modern Manufacturing Quantity Engineering, School of Mechanical Engineering, Hubei University of Technology, Wuhan 430068, China"}]}],"member":"1968","published-online":{"date-parts":[[2022,2,9]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"112109","DOI":"10.1016\/j.sna.2020.112109","article-title":"Orthogonal Optimal Design Method for Point-Focusing EMAT Considering Focal Area Dimensions","volume":"312","author":"Sun","year":"2020","journal-title":"Sens. Actuators A Phys."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Hirao, M., and Ogi, H. (2017). Introduction. Electromagnetic Acoustic Transducers: Noncontacting Ultrasonic Measurements Using EMATs, Springer.","DOI":"10.1007\/978-4-431-56036-4"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"539","DOI":"10.1016\/j.sna.2016.07.006","article-title":"A modified meander-line-coil EMAT design for signal amplitude enhancement","volume":"247","author":"Pei","year":"2016","journal-title":"Sens. Actuators A Phys."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"458","DOI":"10.1016\/j.ndteint.2006.01.003","article-title":"Shear-wave time of flight diffraction (S-TOFD) technique","volume":"39","author":"Baskaran","year":"2006","journal-title":"NDT E Int."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"102212","DOI":"10.1016\/j.ndteint.2019.102212","article-title":"Shear waves with orthogonal polarisations for thickness measurement and crack detection using EMATs","volume":"111","author":"Khalili","year":"2020","journal-title":"NDT E Int."},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Park, J., Lee, J., Min, J., and Cho, Y. (2020). Defects Inspection in Wires by Nonlinear Ultrasonic-Guided Wave Generated by Electromagnetic Sensors. Appl. Sci., 10.","DOI":"10.3390\/app10134479"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"17420","DOI":"10.3390\/s150717420","article-title":"A New Method to Evaluate Surface Defects with an Electromagnetic Acoustic Transducer","volume":"15","author":"Zhang","year":"2015","journal-title":"Sensors"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"102205","DOI":"10.1016\/j.ndteint.2019.102205","article-title":"Small electromagnetic acoustic transducer with an enhanced unique magnet configuration","volume":"110","author":"Sun","year":"2020","journal-title":"NDT E Int."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1299\/jpes.1.3","article-title":"Development of the ISI Device for Fast Breeder Reactor MONJU Reactor Vessel","volume":"1","author":"Tagawa","year":"2006","journal-title":"J. Power Energy Syst."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"106465","DOI":"10.1016\/j.ultras.2021.106465","article-title":"Design of a new type of omnidirectional shear-horizontal EMAT by the use of half-ring magnets and PCB technology","volume":"115","author":"Zhang","year":"2021","journal-title":"Ultrasonics"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"102465","DOI":"10.1016\/j.ndteint.2021.102465","article-title":"Characterising the beam formation of SH waves using double-row Staggered Halbach EMAT configurations","volume":"121","author":"Shankar","year":"2021","journal-title":"NDT E Int."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Shimizu, H., and Bahr, A.J. (1977, January 26\u201328). Improved Design for Non-Contacting Electromagnetic-Acoustic Transducers. Proceedings of the 1977 Ultrasonics Symposium, Menlo Park, CA, USA.","DOI":"10.1109\/ULTSYM.1977.196800"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"102572","DOI":"10.1016\/j.ndteint.2021.102572","article-title":"High-temperature EMAT with double-coil configuration generates shear and longitudinal wave modes in paramagnetic steel","volume":"125","author":"Zhai","year":"2022","journal-title":"NDT E Int."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1115\/1.2748821","article-title":"Combination of Longitudinal and Transverse Ultrasonic Waves for In Situ Control of the Tightening of Bolts","volume":"129","author":"Chaki","year":"2006","journal-title":"J. Press. Vessel. Technol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"6691","DOI":"10.1109\/JSEN.2020.3043389","article-title":"Ultrasonic Measurement of Axial Stress Using High-Frequency Cylindrical Guided Wave","volume":"21","author":"Chen","year":"2020","journal-title":"IEEE Sens. J."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"8883845","DOI":"10.1155\/2020\/8883845","article-title":"Parameter Recognition of Mode-Converted Wave in Single-Source Ultrasound Using Gabor Transform for Bolt Axial Stress Evaluation","volume":"2020","author":"Chen","year":"2020","journal-title":"J. Sens."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"107781","DOI":"10.1016\/j.apacoust.2020.107781","article-title":"Uniaxial stress in-situ measurement using EMAT shear and longitudinal waves: Transducer design and experiments","volume":"175","author":"Liu","year":"2021","journal-title":"Appl. Acoust."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"914","DOI":"10.1016\/j.ultras.2013.11.003","article-title":"Bolt axial stress measurement based on a mode-converted ultrasound method using an electromagnetic acoustic transducer","volume":"54","author":"Ding","year":"2014","journal-title":"Ultrasonics"},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Hirao, M., and Ogi, H. (2017). Available EMATs. Electromagnetic Acoustic Transducers: Noncontacting Ultrasonic Measurements Using EMATs, Springer.","DOI":"10.1007\/978-4-431-56036-4"},{"key":"ref_20","unstructured":"Cunha, M.P.D., and Jordan, J.W. (2005, January 29\u201331). Improved longitudinal EMAT transducer for elastic constant extraction. Proceedings of the 2005 IEEE International Frequency Control Symposium and Exposition, Vancouver, BC, Canada."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"227","DOI":"10.3233\/JAE-141834","article-title":"An improved longitudinal wave EMAT based on the shielding effect","volume":"45","author":"Wu","year":"2014","journal-title":"Int. J. Appl. Electromagn. Mech."},{"key":"ref_22","first-page":"494","article-title":"An improved design of shear horizontal guided wave electromagnetic acoustic transducer","volume":"62","author":"Zhang","year":"2020","journal-title":"Insight-Non-Destr. Test. Cond. Monit."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Xu, Y., Tagawa, A., Ueda, M., Yamashita, T., Ohtsuka, Y., Osafune, K., and Nishikawa, M. (2004). A New Structure of SH Wave Electromagnetic Acoustic Transducer (EMAT). Acoustical Imaging, Springer.","DOI":"10.1115\/PVP2004-2834"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Li, Y., Liu, T., Liu, Y., Liu, H., and Wang, Y. (2019, January 6\u20139). Measurement of Elastic Constants Using Halbach Array Enhanced EMAT. Proceedings of the 2019 IEEE International Ultrasonics Symposium (IUS), Glasgow, UK.","DOI":"10.1109\/ULTSYM.2019.8925751"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Jia, X., Ouyang, Q., and Zhang, X. (2017). An Improved Design of the Spiral-Coil EMAT for Enhancing the Signal Amplitude. Sensors, 17.","DOI":"10.3390\/s17051106"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"296","DOI":"10.1016\/j.sna.2006.01.048","article-title":"A model for pulsed Rayleigh wave and optimal EMAT design","volume":"128","author":"Jian","year":"2006","journal-title":"Sens. Actuators A Phys."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"189","DOI":"10.1016\/j.sna.2018.03.010","article-title":"Enhancement of EMAT\u2019s efficiency by using silicon steel laminations back-plate","volume":"274","author":"Ren","year":"2018","journal-title":"Sens. Actuators A Phys."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/4\/1316\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T22:17:04Z","timestamp":1760134624000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/4\/1316"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,2,9]]},"references-count":27,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2022,2]]}},"alternative-id":["s22041316"],"URL":"https:\/\/doi.org\/10.3390\/s22041316","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,2,9]]}}}