Numerical simulation of ballistic impact behavior of bio-inspired scale-like protection system

The teleost fish scales, such as Grass Carp and Cyprinoid, characterize hierarchical structure which usually consists of a hard bony outer layer and a soft inner cross-ply of collagen fibrils. Each scale overlaps with other neighboring scales, thus fish skin can effectively disperse external loadings with superior flexibility. Inspired by the two-layer structure and overlapping pattern of fish scales, bio-inspired composite scale, and scale-like protection system are designed in this study. Silicon carbide (SiC) ceramic and aluminum are selected as the outer and inner layers of the bio-inspired composite scale, respectively. In this study, the optimal thickness ratio of SiC/Al is chosen as 3:2 through numerical simulation on penetration test and residual velocity analysis of bio-inspired composite scale with LS-DYNA. Compared with pure SiC scales, the area density of bio-inspired composite scale can be reduced by 12.5% with the same ballistic performance at the impact velocity of 878 m/s. Further, a comparative simulation analysis among different overlapping ratios of scale-like protection systems, which consists of overlapped bio-inspired composite scales, is conducted and an optimal overlapping ratio of 0.40 is found. The present numerical study on scale-like protection system enables pathways to design a lightweight and flexible protective system. (C) 2016 Elsevier Ltd. All rights reserved.