PSI - Issue 52

ScienceDirect Structural Integrity Procedia 00 (2023) 000 – 000 Structural Integrity Procedia 00 (2023) 000 – 000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceDirect Available online at www.sciencedirect.com ScienceDirect

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 52 (2024) 647–654

© 2023 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Professor Ferri Aliabadi Abstract Current CFRP aircraft structures can suffer from barely visible impact damage (BVID). These BVIDs can grow due to the operational loads applied on the damaged structure and can eventually even compromise their load-bearing functionality. To detect these BVIDs as soon as possible, aircraft are frequently submitted to on-ground inspections, which increase downtimes and associated costs. A permanently installed sensor network could overcome these shortcomings. Optical fibre sensors have been proposed as possible candidates for such networks owing to their light weight, their small diameter, and their immunity to electromagnetic interference. In this work we use a network of four flight-compatible optical fibres, with a total of 120 fibre Bragg grating (FBG) sensors, to monitor the damage-prone stiffener feet on a large curved CFRP panel of 5 x 3 m 2 . We created BVIDs of calibrated size at the damage-prone locations and we use the response of all 120 sensors to detect and locate the BVIDs. To do so, we first consider temperature effects between the baseline and inspection measurement, and second, we quantify the health of the component based on all sensor readings and test it against a damage threshold. © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Professor Ferri Aliabadi Keywords: optical fibre sensors (OFS), fibre Bragg gratings (FBG), CFRP, barely visible impact damage (BVID), fuselage panel Abstract Current CFRP aircraft structures can suffer from barely visible impact damage (BVID). These BVIDs can grow due to the operational loads applied on the damaged structure and can eventually even compromise their load-bearing functionality. To detect these BVIDs as soon as possible, aircraft are frequently submitted to on-ground inspections, which increase downtimes and associated costs. A permanently installed sensor network could overcome these shortcomings. Optical fibre sensors have been proposed as possible candidates for such networks owing to their light weight, their small diameter, and their immunity to electromagnetic interference. In this work we use a network of four flight-compatible optical fibres, with a total of 120 fibre Bragg grating (FBG) sensors, to monitor the damage-prone stiffener feet on a large curved CFRP panel of 5 x 3 m 2 . We created BVIDs of calibrated size at the damage-prone locations and we use the response of all 120 sensors to detect and locate the BVIDs. To do so, we first consider temperature effects between the baseline and inspection measurement, and second, we quantify the health of the component based on all sensor readings and test it against a damage threshold. © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Professor Ferri Aliabadi Keywords: optical fibre sensors (OFS), fibre Bragg gratings (FBG), CFRP, barely visible impact damage (BVID), fuselage panel Fracture, Damage and Structural Health Monitoring Barely visible impact damage detection and location on a real scale curved CFRP fuselage panel with optical fibre Bragg grating sensors Sidney Goossens a, *, Kirsa Muñoz b , Miguel Jiménez b , María Mora Mendíaz c , Francis Berghmans a a Vrije Universiteit Brussel, Brussels Photonics (B-PHOT) and Flanders Make, Pleinlaan 2, 1050 Brussels, Belgium b Element Materials Technology Seville SL, Wilbur y Orville Wright 1, Seville, San José de la Rinconada 41300, Spain c FIDAMC, Foundation for the Research, Development and Application of Composite Materials, Avda. Rita Levi Montalcini 29, Tecnogetafe, 28906 Getafe, Madrid, Spain Fracture, Damage and Structural Health Monitoring Barely visible impact damage detection and location on a real scale curved CFRP fuselage panel with optical fibre Bragg grating sensors Sidney Goossens a, *, Kirsa Muñoz b , Miguel Jiménez b , María Mora Mendíaz c , Francis Berghmans a a Vrije Universiteit Brussel, Brussels Photonics (B-PHOT) and Flanders Make, Pleinlaan 2, 1050 Brussels, Belgium b Element Materials Technology Seville SL, Wilbur y Orville Wright 1, Seville, San José de la Rinconada 41300, Spain c FIDAMC, Foundation for the Research, Development and Application of Composite Materials, Avda. Rita Levi Montalcini 29, Tecnogetafe, 28906 Getafe, Madrid, Spain

* Corresponding author. Tel.: 0032 2 629 36 58. E-mail address: sidney.goossens@vub.be * Corresponding author. Tel.: 0032 2 629 36 58. E-mail address: sidney.goossens@vub.be

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Professor Ferri Aliabadi 2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Professor Ferri Aliabadi

2452-3216 © 2023 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Professor Ferri Aliabadi 10.1016/j.prostr.2023.12.065