{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T05:40:37Z","timestamp":1774935637336,"version":"3.50.1"},"reference-count":41,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2022,9,11]],"date-time":"2022-09-11T00:00:00Z","timestamp":1662854400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Regional Development Fund (ERDF)","award":["LISBOA-01-0247-FEDER-033948"],"award-info":[{"award-number":["LISBOA-01-0247-FEDER-033948"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>The strengthening of concrete structures with laminates of Carbon-Fiber-Reinforced Polymers (CFRP) is a widely adopted technique. retained The application is more effective if pre-stressed CFRP laminates are adopted. The measurement of the strain level during the pre-stress application usually involves laborious and time-consuming applications of instrumentation. Thus, the development of expedited approaches to accurately measure the pre-stressed application in the laminates represents an important contribution to the field. This paper proposes and benchmarks contact-free architecture for measuring the strain level of CFRP laminate based on computer vision. The main objective is to provide a solution that might be economically feasible, automated, easy to use, and accurate. The architecture is fed by digitally deformed synthetic images, generated based on a low-resolution camera. The adopted methods range from traditional machine learning to deep learning. Furthermore, dropout and cross-validation methods for quantifying traditional machine learning algorithms and neural networks are used to efficiently provide uncertainty estimates. ResNet34 deep learning architecture provided the most accurate results, reaching a root mean square error (RMSE) of 0.057\u2030 for strain prediction. Finally, it is important to highlight that the architecture presented is contact-free, automatic, cost-effective, and measures directly on the laminate surfaces, which allows them to be widely used in the application of pre-stressed laminates.<\/jats:p>","DOI":"10.3390\/ma15186310","type":"journal-article","created":{"date-parts":[[2022,9,13]],"date-time":"2022-09-13T01:44:03Z","timestamp":1663033443000},"page":"6310","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":19,"title":["Benchmarking for Strain Evaluation in CFRP Laminates Using Computer Vision: Machine Learning versus Deep Learning"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0191-0308","authenticated-orcid":false,"given":"J\u00f3natas","family":"Valen\u00e7a","sequence":"first","affiliation":[{"name":"CERIS, IST-ID, University of Lisbon, 1049-003 Lisboa, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3998-0096","authenticated-orcid":false,"given":"Habibu","family":"Mukhandi","sequence":"additional","affiliation":[{"name":"Institute of Systems and Robotics, University of Coimbra, 3030-290 Coimbra, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1507-4945","authenticated-orcid":false,"given":"Andr\u00e9 G.","family":"Ara\u00fajo","sequence":"additional","affiliation":[{"name":"Institute of Systems and Robotics, University of Coimbra, 3030-290 Coimbra, Portugal"},{"name":"Ingeniarius, Lda, 4445-147 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6641-6090","authenticated-orcid":false,"given":"Micael S.","family":"Couceiro","sequence":"additional","affiliation":[{"name":"Institute of Systems and Robotics, University of Coimbra, 3030-290 Coimbra, Portugal"},{"name":"Ingeniarius, Lda, 4445-147 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1690-9887","authenticated-orcid":false,"given":"Eduardo","family":"J\u00falio","sequence":"additional","affiliation":[{"name":"CERIS, IST, University of Lisbon, 1049-001 Lisboa, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2022,9,11]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"63","DOI":"10.1617\/s11527-020-01496-7","article-title":"Structural behaviour of CFRP reinforced concrete members under bending and shear loads","volume":"53","author":"Ghadioui","year":"2020","journal-title":"Mater. 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