Fish scale-cellular composite system for protection against low-velocity impact

Fish scale structures have been known to resist penetration when subject to localized impact, while cellular materials such as cork are lightweight and have good energy absorption capacity. Combining the fish scale structure with cellular material can lead to a composite structure with improved performance against low-velocity impact. In this paper, the feasibility of such composite system is explored as a protective layer against low-velocity impact. Finite element simulations are conducted to investigate the mechanical behavior of the fish scale-cellular composite system, followed by experimental validation of finite element models using drop-weight impact test. Results from simulation indicated that specimens with curved scales produce the lowest peak stress transferred to a protected object or surface, and out-perform sandwich specimens with the same volume of materials. Most importantly, there exists an optimum range for the stiffness and strength of the scales relative to the underlying layer for effective dissipation of the impact energy and minimal stresses transferred to the protected object.