Investigation of the Impact Resistance of Foam‐Filled Combined Honeycomb Structures

ABSTRACT In the field of structural engineering and impact protection, the development of lightweight and high‐strength materials and structural forms has gained significant attention. Honeycomb structures, known for their exceptional specific strength, stiffness, and energy absorption capabilities, are widely used in various applications. However, most studies on the low‐velocity impact performance of honeycomb structures have focused on configurations with a single type of cell element. Therefore, this study investigates the differences in mechanical properties by conducting low‐velocity impact experiments on unit cells combined with different Poisson's ratio characteristics. It also explores the effect of lightweight polyurethane foam filling on the overall performance of the honeycomb structure, while analyzing the influence of punch geometry on the mechanical properties. The findings indicate that honeycomb structures with different cell element combinations exhibit varying mechanical responses under low‐velocity impact, with the combination of elements having a zero Poisson's ratio demonstrating the best impact resistance. Furthermore, the polyurethane foam‐filled honeycomb structure significantly improves energy absorption during impact, with the foam enhancing both the energy absorption capacity and cushioning performance. Additionally, the punch radius has an observable effect on the impact performance.