{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,20]],"date-time":"2026-06-20T06:54:56Z","timestamp":1781938496802,"version":"3.54.5"},"reference-count":31,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2021,1,22]],"date-time":"2021-01-22T00:00:00Z","timestamp":1611273600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000038","name":"Natural Sciences and Engineering Research Council of Canada","doi-asserted-by":"publisher","award":["532228-18"],"award-info":[{"award-number":["532228-18"]}],"id":[{"id":"10.13039\/501100000038","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Time of flight diffraction (TOFD) is considered a reliable non-destructive testing method for the inspection of welds using a pair of single-element probes. On the other hand, ultrasonic phased array imaging has been continuously developed over the last couple of decades, and now features powerful algorithms, such as the total focusing method (TFM) and its multi-view approach to rendering detailed images of inspected parts. This article focuses on a different implementation of the TFM algorithm, relying on the coherent summation of the instantaneous signal phase. This approach presents a wide range of benefits, such as removing the need for calibration, and is highly sensitive to defect tips. This study compares the sizing and localization capabilities of the proposed method with the well-known TOFD. Both instantaneous phase algorithm and TOFD do not take advantage of the signal amplitude. Experimental tests were performed on a \u00be\u2033-thick steel sample with crack-like defects at different angles. Phase-based imaging techniques showed similar characterization capabilities as the standard TOFD method. However, the proposed method adds the benefit of generating an easy-to-interpret image that can help in localizing the defect. These results pave the way for a new characterization approach, especially in the field of automated ultrasonic testing (AUT).<\/jats:p>","DOI":"10.3390\/s21030730","type":"journal-article","created":{"date-parts":[[2021,1,22]],"date-time":"2021-01-22T03:31:30Z","timestamp":1611286290000},"page":"730","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":20,"title":["Towards an Alternative to Time of Flight Diffraction Using Instantaneous Phase Coherence Imaging for Characterization of Crack-Like Defects"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8878-496X","authenticated-orcid":false,"given":"Baptiste","family":"Gauthier","sequence":"first","affiliation":[{"name":"PUL\u00c9TS, \u00c9cole de Technologie Sup\u00e9rieure (\u00c9TS), Montr\u00e9al, QC H3C 1K3, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guillaume","family":"Painchaud-April","sequence":"additional","affiliation":[{"name":"Olympus NDT Canada, Qu\u00e9bec, QC G1P 0B3, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Alain","family":"Le Duff","sequence":"additional","affiliation":[{"name":"Olympus NDT Canada, Qu\u00e9bec, QC G1P 0B3, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7469-4696","authenticated-orcid":false,"given":"Pierre","family":"B\u00e9langer","sequence":"additional","affiliation":[{"name":"PUL\u00c9TS, \u00c9cole de Technologie Sup\u00e9rieure (\u00c9TS), Montr\u00e9al, QC H3C 1K3, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,1,22]]},"reference":[{"key":"ref_1","unstructured":"Groover, M.P. (2007). Fundamentals of Modern Manufacturing: Materials, Processes, and Systems, John Wiley & Sons. [3rd ed.]."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"351","DOI":"10.1115\/1.1991881","article-title":"Review of Ultrasonic Phased Arrays for Pressure Vessel and Pipeline Weld Inspections","volume":"127","author":"Moles","year":"2005","journal-title":"J. Press. Vessel Technol."},{"key":"ref_3","unstructured":"Charlesworth, J.P., and Temple, J.A.G. (2001). Engineering Applications of Ultrasonic Time-of-Flight Diffraction, Research Studies Press. [2nd ed.]."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"701","DOI":"10.1016\/j.ndteint.2005.04.002","article-title":"Post-processing of the full matrix of ultrasonic transmit\u2013receive array data for non-destructive evaluation","volume":"38","author":"Holmes","year":"2005","journal-title":"NDT E Int."},{"key":"ref_5","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_6","doi-asserted-by":"crossref","unstructured":"Schmerr, L.W. (2015). Fundamentals of Ultrasonic Phased Arrays, Springer International Publishing.","DOI":"10.1007\/978-3-319-07272-2"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"1037","DOI":"10.1063\/1.4914712","article-title":"Adaptive ultrasonic imaging with the total focusing method for inspection of complex components immersed in water","volume":"1650","author":"Jeune","year":"2015","journal-title":"AIP Conf. Proc."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1842","DOI":"10.1016\/j.ultras.2013.12.012","article-title":"A comparison between ultrasonic array beamforming and super resolution imaging algorithms for non-destructive evaluation","volume":"54","author":"Fan","year":"2014","journal-title":"Ultrasonics"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Han, X., Wu, W., Li, P., and Lin, J. (November, January 30). Application of ultrasonic phased array total focusing method in weld inspection using an inclined wedge. Proceedings of the 2014 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications, Beijing, China.","DOI":"10.1109\/SPAWDA.2014.6998539"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/j.ndteint.2009.10.001","article-title":"Defect detection using ultrasonic arrays: The multi-mode total focusing method","volume":"43","author":"Zhang","year":"2010","journal-title":"NDT E Int."},{"key":"ref_11","first-page":"1","article-title":"Ultrasonic Flaw Imaging via Multipath Exploitation","volume":"2012","author":"Zhang","year":"2012","journal-title":"Adv. Acoust. Vib."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Yu, P., and Gang, T. (2017, January 22\u201324). The Use of Multi-Mode TFM to Measure the Depth of Small Surface-Break Cracks in Welds. Proceedings of the 2017 Far East NDT New Technology & Application Forum (FENDT), Xi\u2019an, China.","DOI":"10.1109\/FENDT.2017.8584593"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1129","DOI":"10.1109\/TUFFC.2019.2909988","article-title":"A Model for Multiview Ultrasonic Array Inspection of Small Two-Dimensional Defects","volume":"66","author":"Budyn","year":"2019","journal-title":"IEEE Trans. Ultrason. Ferroelectr. Freq. Control"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"012005","DOI":"10.1088\/1742-6596\/1017\/1\/012005","article-title":"Development of methods for the analysis of multi-mode TFM images","volume":"1017","author":"Sy","year":"2018","journal-title":"J. Phys. Conf. Ser."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"134","DOI":"10.1016\/j.ndteint.2018.07.005","article-title":"Development of the specular echoes estimator to predict relevant modes for Total Focusing Method imaging","volume":"99","author":"Sy","year":"2018","journal-title":"NDT E Int."},{"key":"ref_16","unstructured":"Sy, K. (2018). Development of Methods for Defects Characterization Based on TFM Imaging, Universit\u00e9 Paris Saclay (COmUE)."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"958","DOI":"10.1109\/TUFFC.2009.1128","article-title":"Phase Coherence Imaging","volume":"56","author":"Camacho","year":"2009","journal-title":"IEEE Trans. Ultrason. Ferroelectr. Freq. Control"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"164","DOI":"10.1016\/j.ndteint.2017.10.007","article-title":"Ultrasonic crack evaluation by phase coherence processing and TFM and its application to online monitoring in fatigue tests","volume":"93","author":"Camacho","year":"2018","journal-title":"NDT E Int."},{"key":"ref_19","unstructured":"Ginzel, E. (2013). Ultrasonic Time of Flight Diffraction, Eclipse Scientific Products Incorporated."},{"key":"ref_20","first-page":"9","article-title":"Changes in ultrasonic defect location and sizing","volume":"20","author":"Silk","year":"1987","journal-title":"NDT Int."},{"key":"ref_21","unstructured":"ASTM International (2019). Standard Practice for Use of the Ultrasonic Time of Flight Diffraction (TOFD) Technique, ASTM International. E2373\/E2373M-19."},{"key":"ref_22","first-page":"319","article-title":"Application of elastic scattering theory for smooth flat cracks to the quantitative prediction of ultrasonic defect detection and sizing","volume":"22","author":"Coffey","year":"1983","journal-title":"Nucl. Energy"},{"key":"ref_23","unstructured":"Standards, B. (2009). Time-of-flight diffraction technique as a method for detection and sizing of discontinuities. Non-Destructive Testing\u2014Ultrasonic Examination Part 6, International Organization for Standardization."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"259","DOI":"10.1016\/0041-624X(83)90058-6","article-title":"Diffraction of elastic waves by cracks: Application to time-of-flight inspection","volume":"21","author":"Ogilvy","year":"1983","journal-title":"Ultrasonics"},{"key":"ref_25","doi-asserted-by":"crossref","unstructured":"Han, X., Wu, W., Zhang, D., and Wan, H. (2019, January 6\u20139). Combination of direct, half-skip and full-skip TFM to characterize defect(II). Proceedings of the 2019 IEEE International Ultrasonics Symposium (IUS), Glasgow, UK.","DOI":"10.1109\/ULTSYM.2019.8925989"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"080001","DOI":"10.1063\/1.5031558","article-title":"Sensitivity images for multi-view ultrasonic array inspection","volume":"1949","author":"Budyn","year":"2018","journal-title":"AIP Conf. Proc."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Zhang, H., Zeng, L., Fan, G., Zhang, H., Zhu, Q., and Zhu, W. (2020). Instantaneous Phase Coherence Imaging for Near-Field Defects by Ultrasonic Phased Array Inspection. Sensors, 20.","DOI":"10.3390\/s20030775"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"687","DOI":"10.1016\/j.jcp.2013.10.017","article-title":"Accelerated finite element elastodynamic simulations using the GPU","volume":"257","author":"Huthwaite","year":"2014","journal-title":"J. Comput. Phys."},{"key":"ref_29","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_30","doi-asserted-by":"crossref","first-page":"108298","DOI":"10.1016\/j.measurement.2020.108298","article-title":"A metrological approach to the time of flight diffraction method (ToFD)","volume":"167","author":"Mayworm","year":"2021","journal-title":"Measurement"},{"key":"ref_31","unstructured":"Rocha, L., Velho, L., and Carvalho, P.C.P. (2002, January 10). Image moments-based structuring and tracking of objects. Proceedings of the XV Brazilian Symposium on Computer Graphics and Image Processing, Fortaleza, Brazil."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/3\/730\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T05:13:50Z","timestamp":1760159630000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/21\/3\/730"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,1,22]]},"references-count":31,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2021,2]]}},"alternative-id":["s21030730"],"URL":"https:\/\/doi.org\/10.3390\/s21030730","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,1,22]]}}}