Investigation of mechanical properties of aluminum 3003 core honeycomb sandwich structures reinforced with carbon, nylon fibers face sheet and polyurethane foam filler

Lightweight sandwich-based structures are progressively used in the aerospace industries and automotive industries, such as bumper and marine sectors, like rubbing nails in boats, mainly for their high strength-to-weight ratios. Among these, honeycomb cores made of Aluminum 3003 offer excellent stiffness and energy absorption. Enhancing their mechanical performance through reinforcement and optimized filler materials is the predominant focus. This study focuses investigating the mechanical behavior of the Aluminum 3003 honeycomb sandwich structures filled with polyurethane foam reinforced with carbon and nylon fibers. The objective is to improve key mechanical properties, including compressive, tensile, impact, and flexural strength under three-point bending tests by introducing a low-density filler within the honeycomb core. Core, face sheets, and filler materials are selected for optimal energy absorption. Experimental and numerical analyses are conducted to compare performance, with an emphasis on achieving enhanced mechanical properties through filler integration. The findings hold potential for advancing lightweight, high-performance energy-absorbing structures in automotive and marine design. The incorporation of polyurethane (PU) foam significantly enhanced the mechanical performance of the sandwich structures. Compared with the corresponding unfilled configurations, the PU-filled sandwich panels exhibited improvements of 9% in tensile strength, 33% in compressive strength, 28% in flexural strength, and 34% in impact resistance, depending on the face-sheet configuration. The results indicate a significant improvement in mechanical properties, especially with carbon fiber reinforcement. Nylon fibers also showed performance gains, particularly in energy absorption. The reinforced foam acted synergistically with the honeycomb to delay failure and improve stiffness.