JI Junjie, TIAN Yu, ZHANG Chuansheng, WANG Zhen, CHENG Zirui, ZHANG Yanan, HU Yubing
The work aims to study the effect of panel thickness, honeycomb cell size, number of honeycomb wall layers and honeycomb core height on the impact resistance of honeycomb sandwich structures and to determine the parameter combination that yields the optimal impact resistance. A finite element simulation mechanical model of honeycomb sandwich structures under 15 J low velocity impact was established by ABAQUS, and the accuracy of the model was verified by the drop weight test. Then, the fiber-metal laminate (FMLs)/CFRP honeycomb sandwich structures with different structural parameters were designed through orthogonal experiments. According to the range analysis, the effect of the thickness of the FMLs panel, the honeycomb cell size, the number of honeycomb wall layers and the honeycomb core height on the impact resistance of the honeycomb sandwich structures was deeply explored. Finally, the experimental results were compared to obtain the honeycomb sandwich structure with the best impact resistance. The range analysis results showed that the panel thickness was the most significant factor affecting the low velocity impact resistance of the structure, followed by the size of the honeycomb cell, and the height of the honeycomb core and the number of honeycomb wall layers had minor effect. Further findings revealed that with the increase of the panel thickness and the decrease of honeycomb cell size, the maximum displacement of the punch decreased. Conversely, both the peak load and energy absorption increased. A performance evaluation system based on the maximum displacement of punch, peak load and energy absorption is established, and it is found that the honeycomb sandwich structure, composed of 4/3-FMLs, with a honeycomb cell size of 5 mm, three layers of honeycomb walls, and a honeycomb height of 15 mm, exhibits the best impact resistance under 15 J low velocity impact energy.
