PSI - Issue 77

L.A.S. Maia et al. / Procedia Structural Integrity 77 (2026) 87–94 Maia et al. / Structural Integrity Procedia 00 (2026) 000–000

94 8

P m for the DP8005+XNR6852E-2 joint improved with θ decrease. The θ =7.5° model sustained P m =29.68 kN, with corresponding δ =0.865 mm, corresponding to U =13.9 J. Compared to θ =90º, θ =7.5° exhibited 13.9% improvement in P m , and 54.5% in U . Despite the P m improvement, the percentile difference over θ =90º was not as relevant as for the DP8005+AV138 joint. Fig. 9 (b) depicts the effect of the adhesive fillet on P m . The RTV106+AV138 joint exhibited almost no change in P m compared to θ =90°, up to an increase of P m / P 90º =0.8% for θ =60º, due to the weak mechanical properties of RTV106. The other joints (DP8005+XNR6852E-2 and DP8005+AV138) showed a clear P m improvement with the fillet (up to 13.9% and 40.8%, respectively, for θ =7.5º). While both joints benefited from this geometric modification, the DP8005+AV138 joint exhibited the most significant P m increase. 4. Conclusions This study investigated the optimization of DAJ impact strength by CZM using Abaqus ® . The main findings can be summarized as follows: • The DAJ technique, combining a stiff adhesive in the central region and a more flexible adhesive at the edges, significantly improved the impact performance of the joints over SAJ. • Outer chamfers effectively reduced peak σ y and τ xy stresses at the overlap edges, leading to moderate increases in P m and U , up to 14.6% and 16.4%, respectively. • Inner chamfers presented mixed results. Although they alleviated certain stress concentrations, small β negatively impacted P m , particularly for angles below 45°. • Adhesive fillets proved to be the most beneficial geometric modification, with up to 40.8% P m improvement, for the DP8005+AV138 joint. They smoothed stress transitions, significantly reduced stress concentrations, and provided the greatest P m and U increases. Overall, the numerical results validated by experimental benchmarks confirm that the strategic DAJ use and targeted geometric modifications can enhance the impact resistance of adhesively bonded joints. This study provides design guidelines to optimize the performance of structural adhesive joints in industries where impact loading is critical, such as aerospace and automotive sectors. References Brockmann, W., Gei?, P. L., Klingen, J. (2008). Adhesive bonding: materials, applications and technology, Wiley Online Library. Carvalho, D. F. T., Campilho, R. D. S. G., Ramalho, L. D. C., Moreira, R. D. F., Madani, K., 2024. Application of the dual-adhesive technique for static improvement of single-step joints. Procedia Structural Integrity 54: 398-405. Carvalho, P. M. D., Campilho, R. D. S. G., Sánchez-Arce, I. J., Rocha, R. J. B., Soares, A. R. F., 2022. Adhesively-bonded T-joint cohesive zone analysis using dual-adhesives. Procedia Structural Integrity 41: 24-35. Fan, J., Alegría, A. A. R. d., Vassilopoulos, A. P., Michaud, V., 2024. Healable adhesive paste development for thick adhesive joints. Construction and Building Materials 449: 138533. He, X., 2011. A review of finite element analysis of adhesively bonded joints. International Journal of Adhesion & Adhesives 31(4): 248-264. Khan, S. A., Iqbal, M., Mehmood, Z., Afshan, Z. (2021). Numerical Analysis of Static Strength Riveted, Adhesive and Hybrid Joints. 2021 International Conference on Applied and Engineering Mathematics (ICAEM). Kurennov, S., Barakhov, K., Vambol, O., 2023. Topological optimization BI-adhesive double lap adhesive joint. One-dimension model. International Journal of Adhesion and Adhesives 126: 103474. Liao, L., Huang, C., Sawa, T., 2013. Effect of adhesive thickness, adhesive type and scarf angle on the mechanical properties of scarf adhesive joints. International Journal of Solids and Structures 50(25): 4333-4340. Öz, Ö., Özer, H., 2017. An experimental investigation on the failure loads of the mono and bi-adhesive joints. Journal of Adhesion Science and Technology 31(19-20): 2251-2270. Perrella, M., Armentani, E., Lamanna, G., Berardi, V. P., 2024. Comparison among methods for identification of CZM parameters from ENF test. Procedia Structural Integrity 66: 344-349. Raphael, C., 1966. Variable-adhesive bonded joints. Applied Polymer Symposium 3: 99-108. Saeedifar, M., Saleh, M. N., Krairi, A., de Freitas, S. T., Zarouchas, D., 2023. Structural integrity assessment of a full-scale adhesively-bonded bi material joint for maritime applications. Thin-Walled Structures 184: 110487. Valente, J. P. A., Campilho, R. D. S. G., Marques, E. A. S., Machado, J. J. M., da Silva, L. F. M., 2019. Adhesive joint analysis under tensile impact loads by cohesive zone modelling. Composite Structures 222: 110894.