{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,21]],"date-time":"2026-03-21T19:27:27Z","timestamp":1774121247912,"version":"3.50.1"},"reference-count":34,"publisher":"MDPI AG","issue":"16","license":[{"start":{"date-parts":[[2024,8,11]],"date-time":"2024-08-11T00:00:00Z","timestamp":1723334400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Key Natural Science Foundation of China","award":["52130504"],"award-info":[{"award-number":["52130504"]}]},{"name":"National Key Natural Science Foundation of China","award":["52105551"],"award-info":[{"award-number":["52105551"]}]},{"name":"National Natural Science Foundation of China","award":["52130504"],"award-info":[{"award-number":["52130504"]}]},{"name":"National Natural Science Foundation of China","award":["52105551"],"award-info":[{"award-number":["52105551"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>During electromagnetic ultrasonic testing, it is difficult to recognize small-size bottom cracks by time of flight (ToF), and the lift-off fluctuation of the probe affects the accuracy and consistency of the inspection results. In order to overcome the difficulty, a novel composite sensor of an electromagnetic acoustic transducer (EMAT) and pulse eddy current (PEC) is designed. We use the amplitude of a bottom echo recorded by EMAT to identify the tiny bottom crack as well as the amplitude of PEC signals picked up by the integrated symmetric coils to measure the average lift-off of the probe in real time. Firstly, the effects of lift-off and bottom cracks on the amplitude of bottom echo are distinguished by combining the theoretical analysis and finite element method (FEM). And then an amplitude correction method based on the fusion of EMAT and PEC signals is proposed to reduce the impact of lift-off on the defect signal. The experimental results demonstrate that the designed composite sensor can effectively detect a bottom crack as small as 0.1 mm \u00d7 0.3 mm. The signal fusion method can accurately correct the amplitude of defect signals and the relative error is less than \u00b18%.<\/jats:p>","DOI":"10.3390\/s24165196","type":"journal-article","created":{"date-parts":[[2024,8,12]],"date-time":"2024-08-12T11:23:46Z","timestamp":1723461826000},"page":"5196","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Bottom Crack Detection with Real-Time Signal Amplitude Correction Using EMAT-PEC Composite Sensor"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-1864-7809","authenticated-orcid":false,"given":"Yizhou","family":"Guo","sequence":"first","affiliation":[{"name":"School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China"}]},{"given":"Yu","family":"Hu","sequence":"additional","affiliation":[{"name":"School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China"}]},{"given":"Kai","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China"}]},{"given":"Yini","family":"Song","sequence":"additional","affiliation":[{"name":"School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1057-3932","authenticated-orcid":false,"given":"Bo","family":"Feng","sequence":"additional","affiliation":[{"name":"School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2622-4769","authenticated-orcid":false,"given":"Yihua","family":"Kang","sequence":"additional","affiliation":[{"name":"School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8883-1025","authenticated-orcid":false,"given":"Zhaoqi","family":"Duan","sequence":"additional","affiliation":[{"name":"School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, China"}]}],"member":"1968","published-online":{"date-parts":[[2024,8,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1387","DOI":"10.1002\/stc.1655","article-title":"Crack Detection and Characterization Techniques\u2014An Overview","volume":"21","author":"Yao","year":"2014","journal-title":"Struct. Control Health Monit."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1016\/j.ijpvp.2016.11.007","article-title":"A Review on Pipeline Corrosion, in-Line Inspection (ILI), and Corrosion Growth Rate Models","volume":"149","author":"Vanaei","year":"2017","journal-title":"Int. J. Press. Vessel. Pip."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"109093","DOI":"10.1016\/j.matdes.2020.109093","article-title":"A Review of Non-Destructive Testing Techniques for the in-Situ Investigation of Fretting Fatigue Cracks","volume":"196","author":"Kong","year":"2020","journal-title":"Mater. Des."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Ravan, M., Amineh, R.K., Koziel, S., Nikolova, N.K., and Reilly, J.P. (2010, January 16\u201319). Estimation of Multiple Surface Cracks Parameters Using MFL Testing. Proceedings of the 2010 URSI International Symposium on Electromagnetic Theory, Berlin, Germany.","DOI":"10.1109\/URSI-EMTS.2010.5637340"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"545","DOI":"10.1016\/j.measurement.2019.02.064","article-title":"An Application of BRANN and MFL Methods: Determining Crack Type and Physical Properties on M5 Steel Sheets","volume":"138","author":"Ege","year":"2019","journal-title":"Measurement"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"24","DOI":"10.1016\/j.ndteint.2013.09.005","article-title":"Eddy-Current Non-Destructive Testing System for the Determination of Crack Orientation","volume":"61","author":"Hamia","year":"2014","journal-title":"NDT E Int."},{"key":"ref_7","doi-asserted-by":"crossref","unstructured":"Dai, L., Feng, H., Wang, T., Xuan, W., Liang, Z., and Yang, X. (2019). Pipe Crack Recognition Based on Eddy Current NDT and 2D Impedance Characteristics. Appl. Sci., 9.","DOI":"10.3390\/app9040689"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"7449","DOI":"10.1109\/JSEN.2021.3049551","article-title":"Investigation of DC Electromagnetic-Based Motion Induced Eddy Current on NDT for Crack Detection","volume":"21","author":"Yuan","year":"2021","journal-title":"IEEE Sens. J."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"112086","DOI":"10.1016\/j.sna.2020.112086","article-title":"Development of Phased Array Ultrasonic System for Detecting Rail Cracks","volume":"311","author":"Kim","year":"2020","journal-title":"Sens. Actuators A Phys."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1016\/j.ndteint.2006.03.006","article-title":"Ultrasonic Arrays for Non-Destructive Evaluation: A Review","volume":"39","author":"Drinkwater","year":"2006","journal-title":"NDT E Int."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"107276","DOI":"10.1016\/j.ultras.2024.107276","article-title":"Ultrasonic Detection Method Based on Flexible Capillary Water Column Arrays Coupling","volume":"139","author":"Wang","year":"2024","journal-title":"Ultrasonics"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Zhang, J., Liu, M., Jia, X., and Gao, R. (2022). Numerical Study and Optimal Design of the Butterfly Coil EMAT for Signal Amplitude Enhancement. Sensors, 22.","DOI":"10.3390\/s22134985"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"6641","DOI":"10.1109\/JSEN.2016.2587620","article-title":"Multiphysics Modeling of a Lorentz Force-Based Meander Coil Electromagnetic Acoustic Transducer via Steady-State and Transient Analyses","volume":"16","author":"Wang","year":"2016","journal-title":"IEEE Sens. J."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"74","DOI":"10.1016\/j.ndteint.2017.04.001","article-title":"High Temperature EMAT Design for Scanning or Fixed Point Operation on Magnetite Coated Steel","volume":"89","author":"Lunn","year":"2017","journal-title":"NDT E Int."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"316","DOI":"10.1016\/j.ndteint.2010.03.004","article-title":"Efficient Detection of Delamination in Multilayered Structures Using Ultrasonic Guided Wave EMATs","volume":"43","author":"Gao","year":"2010","journal-title":"NDT E Int."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"112213","DOI":"10.1016\/j.sna.2020.112213","article-title":"A Flexible and Noncontact Guided-Wave Transducer Based on Coils-Only EMAT for Pipe Inspection","volume":"314","author":"Liu","year":"2020","journal-title":"Sens. Actuators A Phys."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"549","DOI":"10.1016\/j.fusengdes.2018.03.018","article-title":"Inspection of Delamination Defect in First Wall with a Flexible EMAT-Scanning System","volume":"136","author":"Pei","year":"2018","journal-title":"Fusion Eng. Des."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"113053","DOI":"10.1016\/j.sna.2021.113053","article-title":"An External through Type RA-EMAT for Steel Pipe Inspection","volume":"331","author":"Tu","year":"2021","journal-title":"Sens. Actuators A Phys."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"26","DOI":"10.1016\/j.ultras.2018.03.003","article-title":"Sizing of Flaws Using Ultrasonic Bulk Wave Testing: A Review","volume":"88","author":"Felice","year":"2018","journal-title":"Ultrasonics"},{"key":"ref_20","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_21","first-page":"127","article-title":"Design and Optimization of Electromagnetic Ultrasonic Body Wave Probe Based on Halbach Structure","volume":"39","author":"Zhang","year":"2022","journal-title":"Trans. Nanjing Univ. Aeronaut. Astronaut."},{"key":"ref_22","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_23","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_24","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_25","first-page":"1","article-title":"A Sensor Liftoff Modification Method of Magnetic Flux Leakage Signal for Defect Profile Estimation","volume":"53","author":"Feng","year":"2017","journal-title":"IEEE Trans. Magn."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1109\/TIM.2024.3436092","article-title":"AC Magnetic Flux Leakage Testing With Real-Time Liftoff Compensation Using Double Layer Parallel-Cable Probe","volume":"73","author":"Wang","year":"2024","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"102576","DOI":"10.1016\/j.ndteint.2021.102576","article-title":"Lift-off Performance of Electromagnetic Acoustic Transducers (EMATs) for Surface Acoustic Wave Generation","volume":"126","author":"Xiang","year":"2022","journal-title":"NDT E Int."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"125129","DOI":"10.1088\/1361-6501\/acf1bd","article-title":"A Method for Compensation of Permanent Magnetic Field Perturbation (PMFP) Testing Signal Based on Lift-off Measurement","volume":"34","author":"Hu","year":"2023","journal-title":"Meas. Sci. Technol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"112191","DOI":"10.1016\/j.measurement.2022.112191","article-title":"Reduction of Lift-off Effect in Pulsed Eddy Current Testing for Surface Hardness Classification of Ferromagnetic Steel","volume":"205","author":"Duan","year":"2022","journal-title":"Measurement"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"115319","DOI":"10.1016\/j.sna.2024.115319","article-title":"A Lift-off Measurement and Compensation Method Based on a Comprehensive EMAT-PEC Probe","volume":"372","author":"Duan","year":"2024","journal-title":"Sens. Actuators A Phys."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Wang, S., Li, Z., Kang, L., Hu, X., and Zhang, X. (2011, January 7\u201310). Modeling and Comparison of Three Bulk Wave EMATs. Proceedings of the IECON 2011\u201437th Annual Conference of the IEEE Industrial Electronics Society, Melbourne, VIC, Australia.","DOI":"10.1109\/IECON.2011.6119728"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Hirao, M., and Ogi, H. (2017). Electromagnetic Acoustic Transducers: Noncontacting Ultrasonic Measurements Using EMATs, Springer.","DOI":"10.1007\/978-4-431-56036-4"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1007\/BF00566400","article-title":"Numerical Modelling of the Scattering of Elastic Waves in Plates","volume":"4","author":"Harker","year":"1984","journal-title":"J. Nondestruct. Eval."},{"key":"ref_34","unstructured":"MacLauchlan, D., Clark, S., Cox, B., Doyle, T., Grimmett, B., Hancock, J., Hour, K., and Rutherford, C. (September, January 30). Recent Advancements in the Application of EMATs to NDE. Proceedings of the 16th World Conference on NDT, Montreal, QC, Canada."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/16\/5196\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T15:34:55Z","timestamp":1760110495000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/24\/16\/5196"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,8,11]]},"references-count":34,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2024,8]]}},"alternative-id":["s24165196"],"URL":"https:\/\/doi.org\/10.3390\/s24165196","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,8,11]]}}}