Impact Damage of Aluminum-Composite Sandwich Panels and Constituents

This study investigates the impact failure behavior of aluminum-composite sandwich panels, aluminum sheets, and composite laminates. Aluminum alloy sheets possess excellent ductility and plasticity, while carbon fiber composite sheets exhibit high strength, high rigidity, and superior heat resistance. The sandwich panel structure, composed of two layers of aluminum alloy sheets and a central carbon fiber composite sheet, offers the advantages of being lightweight and high strength. These three types of specimens were subjected to impact energies of 15 J, 25 J, and 50 J. The numerical simulations employ LS-DYNA finite element software, with additional investigations into the energy absorption characteristics, which were employed and compared with the experiment. The experimental results indicate that aluminum alloy sheets only exhibit indentation under all three impact energies. Carbon fiber composite sheets sustain damage without penetration at 15 J but experience penetration failure at 25 J and 50 J. Aluminum-composite sandwich panels exhibit greater resistance to failure as compared to carbon fiber composites. At 15 J and 25 J, the top aluminum layer shows indentation, while the bottom aluminum layer develops cracks. At 50 J, complete penetration occurs. A comparison of damage morphology and force-time curves shows good agreement between the experimental and simulation results. While the carbon fiber composite plate exhibits the highest SEA, it also has the largest damage diameter, indicating more severe damage. In contrast, the aluminum alloy panel has the lowest specific energy absorption (SEA) due to its high weight. The aluminum-composite sandwich panel demonstrates intermediate performance in both damage diameter and SEA, striking a balance between the other two specimens.