Low-velocity impact response of bio-inspired multi-sinusoidal corrugated sandwich structure

This study investigated the low-velocity impact response of bio-inspired multi-sinusoidal corrugated (BMSC) sandwich structures inspired by marine shells. A comprehensive experimental study was conducted with impact energies ranging from 45.09 J to 280.83 J. Finite element simulations using ABAQUS provided detailed insights into the progressive damage mechanisms and impact responses of various BMSC sandwich configurations ( n = 1–5). Four distinct failure modes were categorized, corresponding to different impact energy levels, ranging from localized deformation to complete penetration. The impact force-time and impact force-displacement curves, along with energy absorption characteristics, were analyzed. Results revealed that BMSC sandwich structures exhibit superior impact resistance compared to traditional corrugated designs. The BMSC ( n = 3) achieved the highest specific energy absorption of 2.38 J/g, exceeding the traditional design by over 39 % and more than doubling that of titanium-based carbon-fiber/epoxy laminates, demonstrating significantly enhanced energy absorption efficiency and impact protection performance. These advantages stem from the bio-inspired core design, which facilitates and guides progressive deformation, delaying failure initiation and enhancing energy absorption capability. The research provides an in-depth understanding of the impact response, damage mechanisms, and energy absorption efficiency of BMSC sandwich structures, highlighting their suitability for protective structure applications.