PSI - Issue 79

H.G.E. da Silva et al. / Procedia Structural Integrity 79 (2026) 97–104

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4. Conclusions This work presented an experimental and numerical investigation of sandwich structures subjected to 4BP testing. The results demonstrated that both configurations studied, differing in the orientation of the glass fiber layers, exhibited comparable global mechanical behavior, with only marginal differences in strength and stiffness. Experimental P -  curves provided reliable benchmarks, and the comparison with finite element predictions confirmed that the proposed modelling strategy, which combined CZM for the adhesive, a fractured foam model for the core, and the Tsai-Wu criterion for the skins, can reproduce the structural response with good accuracy. Failure was governed by core shear and local stress concentrations under the loading punches, while the skins remained below critical failure thresholds. These findings confirm that the adopted modelling approach is suitable for predicting stiffness, load-bearing capacity, and failure mechanisms of foam-core sandwich structures under bending loads. Overall, the study proposes a progressive damage modelling approach to capture complex failure modes and provides a validated methodology that can be applied to the design and optimization of lightweight sandwich components. Future work may focus on extending the models to include environmental effects, impact loading, and fatigue, thus extending their applicability to real-world service conditions. References da Silva, H. G. E., Campilho, R. D. S. G., Nóvoa, P. J. R. O., Rocha, R. J. B., Madani, K., Benyettou, M., 2025. Experimental and numerical evaluation of composite sandwich. Procedia Structural Integrity 72: 26-33. Djama, K., Michel, L., Ferrier, E., Gabor, A., 2020. Numerical modelling of a truss core sandwich panel: Influence of the con nectors’ geometry and mechanical parameters on the mechanical response. Composite Structures 245. Duleau, A. J. C. (1820). Essai théorique et expérimental sur la résistance du fer forgé, Mme. Ve. Courcier. Farrokhabadi, A., Ahmad Taghizadeh, S., Madadi, H., Norouzi, H., Ataei, A., 2020. Experimental and numerical analysis of novel multi-layer sandwich panels under three point bending load. Composite Structures 250. Gao, X., Zhang, M., Huang, Y., Sang, L., Hou, W., 2020. Experimental and numerical investigation of thermoplastic honeycomb sandwich structures under bending loading. Thin-Walled Structures 155: 106961. Gupta, A. K., Velmurugan, R., Joshi, M., 2017. Numerical and experimental study of multimode failure phenomena in GFRP laminates of different lay-ups. International Journal of Crashworthiness 23(1): 87-99. He, X., 2011. A review of finite element analysis of adhesively bonded joints. International Journal of Adhesion and Adhesives 31(4): 248-264. Hsu, D. K., 2009. Nondestructive evaluation of sandwich structures: a review of some inspection techniques. Journal of Sandwich Structures & Materials 11(4): 275-291. Noor, A. K., Burton, W. S., Bert, C. W., 1996. Computational models for sandwich panels and shells. Ramalho, L. D., Campilho, R. D., Belinha, J., da Silva, L. F., 2020. Static strength prediction of adhesive joints: A review. International Journal of Adhesion and Adhesives 96: 102451. Sayahlatifi, S., Rahimi, G., Bokaei, A., 2021. Experimental and numerical investigation of sandwich structures with balsa core and hybrid corrugated composite/balsa core under three-point bending using digital image correlation. Journal of Sandwich Structures & Materials 23(1): 94-131. Sayahlatifi, S., Rahimi, G. H., Bokaei, A., 2020. The quasi-static behavior of hybrid corrugated composite/balsa core sandwich structures in four point bending: Experimental study and numerical simulation. Engineering Structures 210: 110361. Szabó, B., Babuška, I., 2021. Finite element analysis: Method, verification and validation. Tarlochan, F., 2021. Sandwich structures for energy absorption applications: A review. Materials 14(16): 4731. Thiagarajan, S., Munusamy, R., 2020. Experimental and numerical study of composite sandwich panels for lightweight structural design. International Journal of Crashworthiness: 1-12. Tserpes, K., Barroso- Caro, A., Carraro, P. A., Beber, V. C., Floros, I., Gamon, W., Kozłowski, M., Santandrea, F., Shahverdi, M., Skejić, D., 2022. A review on failure theories and simulation models for adhesive joints. The Journal of Adhesion 98(12): 1855-1915. Zhang, X., Xu, F., Zang, Y., Feng, W., 2020. Experimental and numerical investigation on damage behavior of honeycomb sandwich panel subjected to low-velocity impact. Composite Structures 236: 111882. Zhu, X., Xiong, C., Yin, J., Yang, Z., Sun, H., Deng, H., Cui, K., Zou, Y., 2023. Four-point bending behaviors of CFRP trapezoidal corrugated sandwich plates. Composite Structures 312: 116884.