Impact resistance of nacre-like composites diversely patterned by 3D printing

Multi-layered composites structured by replicating biological creatures are very promising protective material applicable in various industries for the outstanding mechanical characteristics. Particularly, nacre is the most sought-after creature for biomimicry due to the exceptional impact resistance, secured by hierarchically patterned architecture. Therefore, numerous efforts have been devoted aiming to develop high functional composites by mimicking the nacre. However, optimization of dimensions and material properties for the nacre-like geometry has not been fully investigated thus far. In this study, we utilize a combination of fabrication, testing, and simulation to explore an optimal design of the nacre-like composite. Various types of 3D nacre-like architecture are designed, and corresponding specimens are fabricated using a dual-extruder 3D printer. Under drop weight impact loading, impact performances of each specimen are demonstrated. The test is simulated with finite element models of the nacre-like composite, and the experiment and numerical results are in good agreement. Both results reveal that the nacre-like composite outperforms the monolithic stiff material upon impact. Furthermore, adequate dimensions of each constituent and desirable material properties are determined. This insight on the nacre-like design can be employed as a guideline toward further optimization for a new generation of high-performance material systems.