Energy Absorption and Cushioning Performance of Second-Order Hierarchical Corrugated Sandwich Structures under Static and Dynamic Loads

Renowned for the nature of high specific stiffness and strength, lightweight, and excellent energy absorption capabilities, corrugated sandwich structures have found broad utility in fields such as aerospace and vehicle protection. This study introduces a hierarchical design concept into such structures by proposing a second-order hierarchical corrugated sandwich (SHCS) structure and exploring its mechanical and impact performance. An analytical expression for the peak load is derived, and the discrepancy between the theoretical calculations and the finite element analysis results is within 10%. Using numerical simulation methods, the deformation modes of structures is investigated with different numbers of minor supports (n). The deformation modes of structures are categorized into three modes: progressive buckling, transition buckling, and global buckling. Quasi-static compressive and dynamic impact responses of the structure are further analyzed under various impact velocities and geometric parameters of minor support structure, with particular focus on deformation mechanisms and energy absorption characteristics. The results indicate that under quasi-static compression, the thickness of minor support structure exerts a more significant influence on energy absorption. Increasing the thickness from 0.8 to 1.6 mm enhances the specific energy absorption by 67.3%. Under low-velocity impact, both the peak load and specific energy absorption follow a parabolic trend with increasing minor support panel thickness. During dynamic loading, the energy absorption performance of the structure improves as the impact velocity increases. Under high-velocity impact conditions, the peak load and specific energy absorption show an increasing trend with greater minor support panel thickness.