Nacre-inspired topological design tuning the impact resistant behaviors of composite plates

Nacre is well known for its high strength and toughness owing to its ingenious “brick-and-mortar” microstructure. However, its impact resistance has not been studied as well as its static properties, even though protecting fragile organs from external dynamic loadings is one of its most important functions. The current work systematically studied the impact resistant behaviors and energy absorption mechanisms of nacre-inspired composite plates with the “brick-and-mortar” organization of three typical “brick” reinforcements seen in nacre, namely, flat, dovetail and inverse-dovetail. Through the finite element method simulations, the impact stiffness, energy absorption capacity and primary working mechanisms of the composite plates during impact were analyzed. The results show that the inverse-dovetail microstructure is superior in impact stiffness in the projectile rebounding situation, while the dovetail microstructure is better for its relatively higher energy absorption capacity in both the rebounding and perforation scenarios. In the rebounding scenario the primary energy consuming mechanism is plastic deformation, whereas it converts to spalling and fragmentation in the perforation situation. The tablet aspect ratio plays a significant role in tuning the composites’ impact resistant performance and working mechanisms. These findings and conclusions provide meaningful insights into the design of bioinspired composites with high impact resistance.