PSI - Issue 64

Visal Thay et al. / Procedia Structural Integrity 64 (2024) 925–931 Author name / Structural Integrity Procedia 00 (2019) 000–000

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4.3. Comparison between experimental and analytical result Table 4 show the comparison of the debonding load magnification factor of the experimental result and the analytical result. From the table, Case 0 (without end design) and Case 1 (end design with fillet) give a good agreement between experimental result and analytical result. However, Case 2 (end design with reverse taper) and Case 3 (end design using a reverse taper with a partially chamfered end of the patch plate) shows a high difference between experimental result and analytical result. In case of the reverse taper the stress concentration at the change of the patch plate need to be reconsidered. Due to the characteristic of the used adhesive (Konishi E258R), the plastic analysis needs to be further studied.

Table 4. Comparison between experimental and analytical result.

Debonding load magnification factor

Specimen

Experiment

Analysis

Case 0 Case 1 Case 2 Case 4

1.00 1.40 1.43 1.35

1.00 1.34 2.35 1.88

5. Conclusion In this study, a bending loading test was conducted to evaluate the improvement rate of the debonding load of adhesive joints by the patch plate end design. The result shows that the static strength of the adhesively bonded joint is significantly increased for each patch plate end design. The debonding load of Case 1 to Case 3 of the test specimens with patch plate end design were 1.35 to 1.43 times higher than that of the Case 0. In comparison of experiment result and analytical result, Case 0 and Case 1 provide a good agreement, while Case 2 and Case 3 show a high difference between experiment and analysis. The stress concentration at the change of the patch plate and plastic analysis needs to be further studied. Acknowledgements The authors would like to acknowledge the financial support provided by JSPS KAKENHI Grant Numbers JP22K14314 with gratitude. References Deng, J., Lee, M. M. K., 2007. Behaviour under static loading of metallic beams reinforced with a bonded CFRP plate, Composite Structures, 78(2), 232-242. Japan Society of Civil Engineers (Committee on Hybrid Structures), 2012. Advanced technology of repair and strengthening of steel structures using externally-bonded FRP composites. Hybrid Structure Reports 05. [in Japanese] Japan Society of Civil Engineers (Committee on Hybrid Structures), 2013. Advanced technology of joining for FRP Structures and FRP bonding for steel structures, Hybrid Structure Reports 09. [in Japanese] Japan Society of Civil Engineers (Committee on Hybrid Structures), 2018. Guidelines for repair and strengthening of structures using externally bonded FRP, Hybrid Structure Reports 09. [in Japanese] Lin, F., Sun, J. G., Nakamura, H., Maeda, K., Fukuda, Y., 2011. Experimental study on repair of fatigue cracks using drilled holes and externally bonded CFRP strips, Proceedings of the 66th Annual Conference of the Japan Society of Civil Engineers, I-153, 305-306. [in Japanese] Nakamura, H., Moroi, T., Suzuki, H., Maeda, K., Irube, T., 2005. Repair effects of fatigue cracks initiated at welded joint using CFRP strips, Proceedings of Constructional Steel, 113, 89-96. [in Japanese] Zhao, X. L., 2013. FRP-strengthened metallic structures, CRC Press.