Dynamic Response and Energy Absorption of 5052 Aluminum Honeycombs with Gradient‐Thickness Cell Walls under Low‐Velocity Impact

To enhance the safety performance of traditional honeycomb material by reducing their instantaneous peak load during collisions, a chemical etching technique is employed to process 5052 aluminum honeycombs, fabricating honeycombs with gradient‐thickness cell walls (HGTCW) whose thickness varies linearly along the height direction. Quasistatic and low‐velocity impact compression tests are conducted using an electronic universal testing machine and drop‐weight impact tester, respectively, on both nonetched honeycombs with uniform cell walls (HUCW) and HGTCW, with etching heights of 50, 100, and 150 mm at varying impact velocities. Comparative analysis of energy dissipation mechanisms is performed through FEM using ABAQUS software. Results demonstrate that 5052 aluminum HGTCW can completely eliminate the peak load during compression, with the load exhibiting a gradual linear increase with displacement, until it reaches the plateau stage of the load–displacement curve. The stiffness of HGTCW exhibits a strong correlation with the etching height, showing a progressive reduction with increasing etching height. Furthermore, the specific energy absorption (SEA) of HGTCW improves significantly with increasing etching height and impact velocity. HGTCW specimens with different etching heights exhibit a 23.5–54.6% increase in SEA compared to HUCW specimens under dynamic impact conditions, demonstrating superior energy absorption characteristics.