Mechanical behavior of nacre-inspired CFRP composites by 3D printing

High-performance carbon fiber reinforced polymer (CFRP) composites are essential for many structural applications, however, properties such as strength and toughness are often considered mutually exclusive in CFRP composites. Inspired by the biological structure of nacre, this study offers a new 3D printing strategy for manufacturing nacre-inspired CFRP composites, aiming to overcome the limitations of traditional materials. The geometric parameters of the nacre-inspired brick composites, including waviness angle and aspect ratio were considered to systematically investigate their respective roles in achieving both strength and toughness and reveal the failure and deformation mechanisms through tensile and three-point bending tests. The results indicated the interlocking and appropriate aspect ratio nacre-inspired CFRP composites provides distinct advantages in enhancing both the overall strength and toughness of the structure under tensile loading. It is further shown that the bending property exhibited a significant sensitivity to the waviness angle. As the waviness angle gradually increases from negative to positive, the bending resistance of the sample decreases. The findings regarding deformation, failure modes, and toughening mechanisms shed light on how geometric parameters affect the mechanical performance of the nacre-inspired CFRP composites.