PSI - Issue 42

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2019) 000 – 000 Available online at www.sciencedirect.com ^ĐŝĞŶĐĞ ŝƌĞĐƚ

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Procedia Structural Integrity 42 (2022) 1306–1313

23 European Conference on Fracture - ECF23 Damage Detection of CFRP Filament Wound Tubes Using Electrical Resistance Measurement Nikola Schmidová a , Tomáš Ponížil b , Bohumil Kropík a , David Blaha a , Zuzana Tatíčková c , Milan Dvořák a , Karel Doubrava a , Milan Růžička a a Department of Mechanics, Biomechanics and Mechatronics, �aculty of Mechanical Engineering, ��ech Technical University in �rague, Technic�� �, �rague, ��ech �e�ublic, nikola.schmidova@fs.cvut.cz b �om�o Tech ��US, s�ol� s r� o�, No vá áááá, Suáice, ááech áeáublic c Department of Manufacturing Technology, Faculty of Mechanical Engineering, Czech Technical University in Prague, Technická 4, Prague, Czech Republic Abstract The electrical resistance measurement method was used for damage detection of Carbon Fiber Reinforced Polymer (CFRP) tubes during torsion and flexural loading. The symmetrical convex octagon shape specimens were manufactured using a filament winding technology. The specimens were manufactured with Integrated Loop Technology (ILT) joints at the ends in a single production step. This configuration of tubes with ILT joints allows very effective load transfer and it is also efficient from the manufacturing point of view. This type of components could be used in construction of robotic arms for automated processes. Possible collisions and resulting overloading can cause damage to the composite tubes. Such damage could be overlook due to cabling, coating and casing covering the surface of the robotic arms. In addition to the above, the requirement for a smooth surface must also be met. Therefore, possible way how to easily detect serious damage of CFRP tubes was investigated, together with a testing of a novel approach to an electrical contact manufacturing. The electrical contacts for damage monitoring were made of carbon fiber tows with electrically connected endings. They were integrated to the composite structure during filament winding process. Four specimens were loaded by flexural loading and two specimens were loaded by torsional loading. All specimens were loaded by three cycles of operational loading and then loaded to final fracture. It was shown that the presented type of electrical connection to the structure is feasible, does not disturb the surface of the sample and does not affect the ultimate strength of the specimen. According to our measurements, operational loading could be monitored only to a limited extend using the electrical resistance measurement. This is because the fracture damage caused significant change in measured electrical resistance of the specimen for both torsional and flexural loading. The presented measurement configuration with electrodes made of integrated carbon fibers is suitable for further investigation in the field of fracture damage detection of carbon fiber wound profiles. © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/) Peer-review under responsibility of 23 European Conference on Fracture - ECF23

2452-3216 © 2022 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 the scientific committee of the 23 European Conference on Fracture – ECF23 10.1016/j.prostr.2022.12.166