{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,21]],"date-time":"2025-11-21T06:33:51Z","timestamp":1763706831079,"version":"build-2065373602"},"reference-count":34,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2024,6,19]],"date-time":"2024-06-19T00:00:00Z","timestamp":1718755200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Project \u201cHi-rEV\u2014Recupera\u00e7\u00e3o do Setor de Componentes Autom\u00f3veis\u201d","award":["C644864375-00000002"],"award-info":[{"award-number":["C644864375-00000002"]}]},{"name":"\u201cPlano de Recupera\u00e7\u00e3o e Resili\u00eancia\u201d (PRR), \u201cRep\u00fablica Portuguesa\u201d","award":["C644864375-00000002"],"award-info":[{"award-number":["C644864375-00000002"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Processes"],"abstract":"<jats:p>Due to the high abrasiveness and anisotropic nature of composites, along with the need to machine different materials at the same time, drilling multi-materials is a difficult task, and usually results in material damage, such as uncut fibres and delamination, hindering hole functionality and reliability. Image processing and analysis algorithms can be developed to effectively assess such damage, allowing for the calculation of delamination factors essential to the quality control of hole inspection in composite materials. In this study, a digital image processing and analysis algorithm was developed in Python to perform the delamination evaluation of drilled holes on a carbon fibre reinforced polymer (CFRP) and aluminium (Al) multi-material. This algorithm was designed to overcome several limitations often found in other algorithms developed with similar purposes, which frequently lead to user mistakes and incorrect results. The new algorithm is easy to use and, without requiring manual pre-editing of the input images, is fully automatic, provides more complete and reliable results (such as the delamination factor), and is a free-of-charge software. For example, the delamination factors of two drilled holes were calculated using the new algorithm and one previously developed in Matlab. Using the previous Matlab algorithm, the delamination factors of the two holes were 1.380 and 2.563, respectively, and using the new Python algorithm, the results were equal to 3.957 and 3.383, respectively. The Python results were more trustworthy, as the first hole had a higher delamination area, so its factor should be higher than that of the second one.<\/jats:p>","DOI":"10.3390\/pr12061258","type":"journal-article","created":{"date-parts":[[2024,6,19]],"date-time":"2024-06-19T04:21:28Z","timestamp":1718770888000},"page":"1258","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Image Analysis Techniques Applied in the Drilling of a Carbon Fibre Reinforced Polymer and Aluminium Multi-Material to Assess the Delamination Damage"],"prefix":"10.3390","volume":"12","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-5599-6162","authenticated-orcid":false,"given":"R\u00faben D. F.","family":"Sousa Costa","sequence":"first","affiliation":[{"name":"Laborat\u00f3rio Associado em Energia, Transportes e Aeron\u00e1utica, Rua Dr. Roberto Frias 400, 4200-465 Porto, Portugal"},{"name":"Departamento de Engenharia Mec\u00e2nica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"}]},{"given":"Marta L. S.","family":"Barbosa","sequence":"additional","affiliation":[{"name":"Departamento de Engenharia Mec\u00e2nica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4662-3436","authenticated-orcid":false,"given":"Filipe G. A.","family":"Silva","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio Associado em Energia, Transportes e Aeron\u00e1utica, Rua Dr. Roberto Frias 400, 4200-465 Porto, Portugal"},{"name":"Instituto Polit\u00e9cnico Gaya (ISPGaya), Av. dos Descobrimentos 333, 4400-103 Vila Nova de Gaia, Portugal"},{"name":"proMetheus, Instituto Polit\u00e9cnico de Viana do Castelo, Rua Escola Industrial e Comercial Nun\u2019\u00c1lvares, 4900-347 Viana do Castelo, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1368-108X","authenticated-orcid":false,"given":"Tiago E. F.","family":"Silva","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio Associado em Energia, Transportes e Aeron\u00e1utica, Rua Dr. Roberto Frias 400, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1059-715X","authenticated-orcid":false,"given":"Ab\u00edlio M. P.","family":"de Jesus","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio Associado em Energia, Transportes e Aeron\u00e1utica, Rua Dr. Roberto Frias 400, 4200-465 Porto, Portugal"},{"name":"Departamento de Engenharia Mec\u00e2nica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8570-4362","authenticated-orcid":false,"given":"Francisco J. G.","family":"Silva","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio Associado em Energia, Transportes e Aeron\u00e1utica, Rua Dr. Roberto Frias 400, 4200-465 Porto, Portugal"},{"name":"CIDEM, ISEP, Polit\u00e9cnico do Porto, Rua Dr. Bernardino de Almeida 431, 4200-072 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0002-5836","authenticated-orcid":false,"given":"Lu\u00eds M. P.","family":"Dur\u00e3o","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio Associado em Energia, Transportes e Aeron\u00e1utica, Rua Dr. Roberto Frias 400, 4200-465 Porto, Portugal"},{"name":"CIDEM, ISEP, Polit\u00e9cnico do Porto, Rua Dr. Bernardino de Almeida 431, 4200-072 Porto, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7603-6526","authenticated-orcid":false,"given":"Jo\u00e3o Manuel R. S.","family":"Tavares","sequence":"additional","affiliation":[{"name":"Laborat\u00f3rio Associado em Energia, Transportes e Aeron\u00e1utica, Rua Dr. Roberto Frias 400, 4200-465 Porto, Portugal"},{"name":"Departamento de Engenharia Mec\u00e2nica, Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2024,6,19]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"787","DOI":"10.1016\/j.aej.2017.01.020","article-title":"Crack detection using image processing: A critical review and analysis","volume":"57","author":"Mohan","year":"2018","journal-title":"Alex. Eng. J."},{"key":"ref_2","unstructured":"Gonzalez, R.E., and Rafael, C. (2008). Woods, Digital Image Processing, Taylor & Francis. 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