PSI - Issue 42

Nikola Schmidová et al. / Procedia Structural Integrity 42 (2022) 1306–1313 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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electrical contacts and values of maximal strength for the specimens without integrated contacts. The results are given in Fig. 7.

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Fig. 7 (a) Comparison of relative maximal bending moments of specimens with and without electrical contacts; (b) Comparison of relative maximal torsional moments of specimens with and without electrical contacts. 4. Conclusions The ER measurement method was used for fracture monitoring of CFRP composite wound specimens with ILT joints. The novel approach in electrical contact preparation was tested. It was shown, that functional electrical contacts can be integrated during winding process of the composite tubes. The 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. When compared the investigated types of loading, the presented configuration of measurement seems more convenient for the monitoring of operational loading during torsional loading compared to flexural loading. Nevertheless, further improvements in the manufacturing process could be carried out. According to our investigation, we consider the presented measurement configuration with electrodes made of integrated carbon fibers suitable for further investigation in the field of fracture damage detection of carbon fiber wound profiles. Acknowledgements This work has been supported by project No. TJ02000252 of the Technological agency of the Czech Republic. References Schulte, K., Baron, C., 1989. Load and Failure analyses of CFRP laminates by means of electrical resistivity measurements, Compos Sci Technol 36, 63-76. Todoroki, a., Ueda, M., Hirano, Y., 2007. Strain and Damage Monitoring of CFRP Laminates by Means of Electrical Resistance Measurement, Journal of Solid Mechanics and Materials Engineering 1, 947-974. Böger, L., Wichmann, M., Meze, L., Schulte, K., 2008. Load and health monitoring in glass fibre reinforced composites with an electrically conductive nanocomposite epoxy matrix, Compos Sci Technol 68, 1886-1894. Todoroki, A., Tanaka, M., Shimamura, Y. 2002. Measurement of orthotropic electric conductance of CFRP laminates and analysis of the effect on delamination monitoring with an electric resistance change method, Compos Sci Technol, 619-628. Wang, S., Chung, D.D.L., Chung, J.H. 2005. Impact damage of carbon fibre polymer-matrix composites, studied by electrical resistance measurement, Composites 36, 1707-1715. Wang, S., Chung, D.D.L., Chung, J.H., 2006. Self-sensing of Damage in Carbon Fiber Polymer-Matrix Composite Cylinder by Electrical Resistance Measurement, Journal of Inteligent Material Systems and Structures 16, 57-62. Kwon, D.-J., Shin, P.-S.,Kim, J.-H., Wang, Z.-J., DeVries, K.L., Park, J.-M., 2016. Detection of damage in cylindrical parts of carbon fiber/epoxy composites using electrical resistance (ER) measurements, Composites Part B 99, 528-532.