{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,12]],"date-time":"2026-10-12T00:15:58Z","timestamp":1791764158872,"version":"4.3.4"},"reference-count":24,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T00:00:00Z","timestamp":1775606400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>This study presents a unified mechanics-based framework for evaluating bonded composite patch repairs. Discrete fracture, fatigue, and adhesive responses are transformed into continuous master equations over the design space. Low-order polynomial surfaces model stress intensity and concentration responses, enabling continuous prediction of repair performance without repeated finite-element analyses. A fracture-based repair efficiency index is derived from the analytical master surface. This index quantifies the average reduction in crack-driving force across the domain. Combined with adhesive stiffness and strength, it defines an adhesive-based repair efficiency index (A-REI), providing a direct link between structural response and material properties. The results show that repair effectiveness is strongly influenced by both geometric severity and adhesive properties. Fatigue performance decreases significantly with increasing notch ratio in single-sided repairs. Double-sided configurations maintain consistently higher efficiency. Symmetric reinforcement more effectively reduces stress concentration, with improvements exceeding 40% at intermediate notch ratios. Adhesive selection is governed by stiffness and strength. Structural adhesives achieve significantly higher A-REI values, whereas compliant adhesives contribute negligibly. Overall, repair symmetry controls the magnitude of improvement, while adhesive properties determine performance ranking. This framework provides a clear, practical basis for design and material selection.<\/jats:p>","DOI":"10.3390\/polym18080912","type":"journal-article","created":{"date-parts":[[2026,4,9]],"date-time":"2026-04-09T07:48:07Z","timestamp":1775720887000},"page":"912","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Fracture and Fatigue Assessment of Bonded Composite Patch Repairs in Notched and Cracked Plates"],"prefix":"10.3390","volume":"18","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3204-6746","authenticated-orcid":false,"given":"Bertan","family":"Beylergil","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering, Alanya Alaaddin Keykubat University, Alanya, Antalya 07450, Turkey"},{"name":"Composite Technologies Center of Excellence, Istanbul Technology Development Zone, Sabanci University, Pendik, Istanbul 34906, Turkey"},{"name":"Faculty of Engineering and Natural Sciences, Sabanci University, Tuzla, Istanbul 34956, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8591-8993","authenticated-orcid":false,"given":"Hasan","family":"Ulus","sequence":"additional","affiliation":[{"name":"Composite Technologies Center of Excellence, Istanbul Technology Development Zone, Sabanci University, Pendik, Istanbul 34906, Turkey"},{"name":"Huglu Vocational School, Selcuk University, Konya 42710, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6314-5261","authenticated-orcid":false,"given":"Mehmet Emin","family":"\u00c7etin","sequence":"additional","affiliation":[{"name":"Aeronautical Engineering Department, Necmettin Erbakan University, Konya 42090, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2312-7106","authenticated-orcid":false,"given":"Halil Burak","family":"Kaybal","sequence":"additional","affiliation":[{"name":"Department of Industrial Design, Faculty of Fine Arts, Kirikkale University, Kirikkale 71450, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9204-5868","authenticated-orcid":false,"given":"Sefa","family":"Yildirim","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, Alanya Alaaddin Keykubat University, Alanya, Antalya 07450, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Abdulrahman","family":"Al-Nadhari","sequence":"additional","affiliation":[{"name":"Composite Technologies Center of Excellence, Istanbul Technology Development Zone, Sabanci University, Pendik, Istanbul 34906, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1626-5858","authenticated-orcid":false,"given":"Mehmet","family":"Yildiz","sequence":"additional","affiliation":[{"name":"Composite Technologies Center of Excellence, Istanbul Technology Development Zone, Sabanci University, Pendik, Istanbul 34906, Turkey"},{"name":"Faculty of Engineering and Natural Sciences, Sabanci University, Tuzla, Istanbul 34956, Turkey"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,8]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1613","DOI":"10.1016\/j.ijfatigue.2009.04.006","article-title":"Experimental and numerical study of the fatigue behaviour of composite patch reinforced cracked steel plates","volume":"31","author":"Tsouvalis","year":"2009","journal-title":"Int. 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