Experimental study of the impact characteristics of sandwich composites with aluminum honeycomb cores

Increasingly severe requirements for metallic materials used in industrial applications are driving the development of composite materials to meet specifications that exceed the properties of single materials. In this study, the mechanical properties of composites with porous cores were examined with impact tests. These composite specimens were sandwich structures with aluminum honeycomb cores, and impact energies such as 50, 70, and 100 J were applied. When a maximum load of 4.5 kN was applied, the striker penetrated the upper face sheet in every case. The maximum load was observed at 4.0, 3.5, and 3.0 ms for impact energies of 50, 70, and 100 J, respectively, indicating that the maximum load occurred sooner when the impact energy was greater. After this point of maximum load, the striker penetrated and broke this material. Penetration of aluminum honeycomb core sandwiches depended on the impact energy. Below 50 J, the striker did not penetrate the lower face sheet, and the honeycomb core sandwich was stable. According to this result, the maximum load occurred when the striker penetrated the upper face sheet. As the striker penetrated a composite, the load gradually decreased after the striker penetrated the core, remained constant, and then increased rapidly after the striker came in contact with the lower face sheet. Simulation results agreed with experimental observations, and all experimental data from this study were verified. These experimental results can be applied to actual conditions in the field. The stability of aluminum honeycomb core sandwich composite structures can be predicted from these experimental results.