PSI - Issue 54

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Author name / Structural Integrity Procedia 00 (2019) 000 – 000

Jaroslav Václavík et al. / Procedia Structural Integrity 54 (2024) 294–299

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Table 1. Maximum forces and corresponded displacements reached during the 3-point bending test with hollow profiles t = 3 mm t = 2 mm Sample F max [kN] s max [mm] F max [kN] s max [mm] Steel 24 6.8 12.9 10.6 CFRP 25.6 6.4 13.2 9.3 CFRP+PUR 30.1 8 Ͳ Ͳ CFRP+EP 29.5 7.2 Ͳ Ͳ

4. Conclusion The use of stiffened hollow profiles with the CFRP plates can on several joints increase the strength of the bus structure. This results in an increase in service life and a delay in the occurrence of cracks and their propagation. The beginnings and ends of the CFRP plates must lie in areas under the debonding limit stress. These areas can be determined using FEM calculation and verified using measurement with strain gauges. In properly designed hybrid structure the hybrid beams must not delaminate during the bus service life to be able withstand the roll over accident. Acknowledgements The article has originated in the framework of M-ERA.NET call 2019 and was supported with Technological Agency of Czech Republic under the No. TH71020003. References Larodé E. at al. A new concept of a bus structure made of composite materials by using continuous transversal frames. Composite Structures 32 (1995), 345-356. Jahn J at al. Assessment strategies for composite-metal joining technologies – A review. 26th CIRP Design Conference, Procedia CIRP 50 (2016), 689 – 694. Galvez P at all. Study of the behavior of adhesive joints of steel with CFRP for its application in bus structures. Composites Part B 129 (2017), 41-46. Bocciarelli, M., Colombi, P., Fava, G. & Poggi, C. 2014, Some issues on the strengthening of steel structures with fibre-reinforced polymer materials, Australian Journal of Structural Engineering, Vol. 15, No. 4, October, 337-354. Kriescher M. at al. Possibilities for the use of metal-hybrid-structures for vehicle crash load cases. Proceedings of 1. International Conference Euro Hybrid Materials and Structures 2014, 10-11. April 2014, Stade, Germany. Laubrock, M. Design of load-bearing adhesive joints in agricultural machinery. Sika Vehicle Manufacturing Days 2022. Václavík, J. at al. Fatigue Behavior of the Hybrid Beam, Proceedings of 27 th International Conference on Fracture and Structural Integrity (IGF27), Procedia Structural Integrity 47 (2023) 282 – 289, ISSN: 2452-3216.