Experimental Investigation of the Flexural Behavior of Sandwich Structures with Carbon Nanotube-Reinforced Composite Faces and Polymeric Hybrid Core

Bensaeed, Ali; Mousavi, Seyed Ali; Shokrollahi, Hassan; Sabouri, Hadi

doi:10.22068/jstc.2025.2073291.1937

Experimental Investigation of the Flexural Behavior of Sandwich Structures with Carbon Nanotube-Reinforced Composite Faces and Polymeric Hybrid Core

Document Type : Research Paper

Authors

Ali Bensaeed

Seyed Ali Mousavi

Hassan Shokrollahi

Hadi Sabouri

Department of Mechanical Engineering, Kharazmi University, Tehran.

10.22068/jstc.2025.2073291.1937

Abstract

The application of composite structures has rapidly expanded in aerospace, automotive, and construction industries, accelerating the development of advanced sandwich panels with diverse applications. In this study, a lightweight sandwich panel was designed and fabricated, consisting of glass fiber–reinforced composite faces reinforced with 0.3 wt% carbon nanotubes and a hybrid polymeric core based on XPS and PU foams. To enhance load transfer and core shear stability, internal GFRP rods were employed as reinforcements. The fabrication process included CNT dispersion in resin, hand lay-up, and cold pressing. The cores were assembled in different sequences and bonded to the facesheets using PVA adhesive. Three-point bending tests were performed in accordance with ASTM C393, and parameters such as peak load, initial stiffness, failure displacement, total absorbed energy, and specific energy absorption (SEA) were evaluated. Results demonstrated that CNT incorporation significantly improved interfacial adhesion and effective modulus, leading to increased stiffness, peak load, and energy contribution. In CNT-containing configurations, peak load reached 700–1000 N, absorbed energy exceeded 20 J, and failure displacement was approximately 50 mm. Comparison of uniform cores revealed that XPS provided higher stiffness, while PU offered greater ductility and final displacement. In hybrid cores, the XPX arrangement (XPS in outer layers) achieved higher stiffness and SEA, whereas the PXP configuration (PU in outer layers) resulted in greater total energy absorption and failure displacement. Overall, optimizing core architecture combined with CNT-reinforced facesheets can simultaneously enhance flexural strength, energy absorption, and ductility, providing a simple and scalable pathway for producing lightweight panels.

Highlights

[1] Chowdhary, S., Tafesse, B., Kebede, M. K., Arumugam, A. B., “Bending behavior of laminated honeycomb core sandwich GFRP composite plate hybrid with MWCNT fillers,” in AIP Conference Proceedings, Vol. 2341, No. 1, p. 020048, 2021.

[2] Ma, Q., Rejab, M. R. M., Siregar, J. P., Guan, Z., “A review of the recent trends on core structures and impact response of sandwich panels,” Journal of Composite Materials, Vol. 55, No. 18, pp. 2513-2555, 2021.

[3] Kamble, Z., “Advanced structural and multi-functional sandwich composites with prismatic and foam cores: A review,” Polymer Composites, Vol. 45, No. 18, pp. 16355-16382, 2024.

[4] Mack, J. P., Mirza, F., Banik, A., Khan, M. H., Tan, K. T., “Hybridization of face sheet in sandwich composites to mitigate low temperature and low velocity impact damage,” Composite Structures, Vol. 338, p. 118101, 2024.

[5] Mirza, F., Mack, J. P., Banik, A., Khan, M. H., Tan, K. T., “Post impact flexural behavior investigation of hybrid foam-core sandwich composites at extreme Arctic temperature,” Composites Science and Technology, Vol. 258, p. 110897, 2024.

[6] Hosseini, S. A., Shokrollahi, H., Mousavi, S. A., Sabouri, H., “Experimental investigation of bending behavior of sandwich structures with auxetic core made of biodegradable materials,” In Persian, Iranian Journal of Manufacturing Engineering, Vol. 12, No. 4, pp. 63-75, 2025.

[7] Mandegarian, S., Hojjati, M., Moghaddar, H., “Recycled PET foam core sandwich panels with reinforced hybrid composite facesheets: A sustainable approach for enhanced impact resistance,” Journal of Sandwich Structures and Materials, Vol. 27, No. 2, pp. 396-428, 2025.

[8] Cai, Y., Wang, X., Ouyang, F., Chen, Q., Zhu, Z., Fan, K., Ding, F., “Study on the mechanical properties of a carbon-fiber/glass-fiber hybrid foam sandwich structure,” Materials, Vol. 17, No. 9, 2023.

[9] Meng, X., Zhang, D., Feng, P., Zhai, J. Q., Liu, T. Q., “Flexural behavior of singly curved GFRP sandwich panel with polyurethane foam core,” Engineering Structures, Vol. 314, p. 118389, 2024.

[10] Najafi, M., Eslami-Farsani, R., “Design and characterization of a multilayered hybrid cored-sandwich panel stiffened by thin-walled lattice structure,” Thin-Walled Structures, Vol. 161, p. 107514, 2021.

[11] Patekar, V., Kale, K., “State of the art review on mechanical properties of sandwich composite structures,” Polymer Composites, Vol. 43, No. 9, pp. 5820-5830, 2022.

[12] Zhao, T., Yang, J., Chen, J., Guan, S., “Review of carbon fiber-reinforced sandwich structures,” Polymers and Polymer Composites, Vol. 30, p. 09673911221098729, 2022.

[13] Gojny, F. H., Wichmann, M. H. G., Köpke, U., Fiedler, B., Schulte, K., “Carbon nanotube-reinforced epoxy-composites: Enhanced stiffness and fracture toughness at low nanotube content,” Composites Science and Technology, Vol. 64, No. 15, pp. 2363-2371, 2004.

[14] Tao, Q., Ren, P., Shi, L., Zhao, Z., Tang, Y., Ye, R., Zhang, W., Cui, J., “Energy absorption and impact behavior of composite sandwich panels under high-velocity spherical projectile,” International Journal of Impact Engineering, Vol. 162, p. 104143, 2022.

Keywords

Sandwich Panels

CNTs

Hybrid Core

GFRP

Subjects