A Novel Interlocking Biomimetic Honeycomb Bridge Protection Device with Enhanced Energy Absorption and Replaceability

The rapid development of waterborne transportation has increased the risk of vessel–bridge collisions, posing significant threats to bridge safety. However, existing protective installations often suffer from limited adaptability and high maintenance costs. Inspired by the superior compressive strength of the elytral joint structure of the iron-ringed beetle, a novel biomimetic thin-walled honeycomb energy-absorbing system was developed by integrating this joint structure with hexagonal and concave honeycomb cells. The mechanical performance of the proposed system was systematically investigated through quasi-static compression experiments and finite element (FE) simulations. By controlling the relative density, the influence of cross-sectional dimensional variations on the mechanical response was further analyzed. Results show that the system exhibits a distinctive secondary plateau stress during impact loading, with the second plateau stress increasing by 328% compared to the first. Furthermore, a pier protection device based on the proposed structure was designed and applied to the Jinma Bridge. Numerical simulations indicate that the peak vessel impact force can be reduced by up to 63.4%. Compared with conventional monolithic protection systems, the proposed interlocking modular system allows discrete unit assembly, providing improved adaptability, reduced material consumption, and higher replacement efficiency. This study offers a novel biomimetic design strategy for bridge protection systems subjected to impact loading.