PSI - Issue 64

Maciej Kulpa et al. / Procedia Structural Integrity 64 (2024) 1339–1346 Kulpa / Structural Integrity Procedia 00 (2019) 000 – 000

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The longitudinal axis strains of the panel recorded by the lower and upper sensors in subsequent loading stages are shown in Fig. 9. The analysis of the strains measured by the sensors in the middle of the upper (U6) and lower laminate (L6) in subsequent loading stages confirms the symmetrical behaviour of the panel and the absence of signs of disturbance (Fig. 9). 4. Conclusions The presented work included the successful adaptation of the existing supporting structure for a heat pipeline as a footbridge. The combination of two functions of the footbridge forced the use of an easy-to-dismantle solution as the deck slabs used to cover the twin plate girders. Due to the lightweight and durability, it was decided to use the FRP composite panels. Two of them were equipped with a DFOS monitoring system to control the behaviour of the panels during service. After reconstruction, the entire structure was tested under the proof load to check the DFOS system and the FRP panels themselves. The results obtained revealed the low stress state in the FRP laminates (approx. 6 MPa) and the fully elastic behaviour of the tested panels. At the same time, DFOS measurements enabled to find local strain peaks which are not dangerous at the moment but should be additionally checked in the planned non-destructive diagnostic tests with use of an ultrasonic method. Owing to the installation of the DFOS system, the FRP panels will be monitored during service and will be subjected to the same loading patterns while the subsequent load tests will be carried out. Comparing the results of subsequent tests will give a clear answer about the operation of this kind of new structure over time. Acknowledgements This project was co-financed by the Minister of Science and Higher Education under the "Regional Excellence Initiative" program under contract no. RID/SP/0032/2024/01 entitled "Regional Center of Excellence in Engineering for Quality of Life and Technology Development ” . References Kulpa, M., Howiacki, T., Wiater, A., Siwowski, T., & Sieńko, R. , 2021. Strain and displacement measurement based on distributed fibre optic sensing (DFOS) system integrated with FRP composite sandwich panel. Measurement, 175, 109099. Olivier, G., C sillag, F., Christoforidou, A., Tromp, L., Veltkamp, M., & Pavlovic, M. , 2023. Feasibility of bolted connectors in hybrid FRP - steel structures. Construction and Building Materials, 383, 131100. Veltkamp, M., 2019 . Eurocode and the Design, Manufacture and I nstallation of 62 Clear Span FRP Bridges to the City of Rotterdam (NL). In 9th Australian Small Bridges Conference, Surfers Paradise, Queensland, Australia . Yang, J., Haghani, R., Valvo, P. S., Ricci, F., & Veltkamp, M., 2017. A new concept for sustainable refurbishment of existing bridges using FRP materials. In Proceedings of SMAR 2017 Conference , Zurich, Switzerland.