Exploiting fiber control for delayed failure in 3D printed fiber reinforced polymer composites

3D printing technology has shown capabilities in producing radical shapes with unique infill patterns and configurations to enhance fiber reinforced polymer composites. The ability to use 3D printing technology to inherently transform FRP failure and post-peak behavior is an unexplored area that can provide a new class of FRP with improved failure behavior. In this study, four designs are developed with combinatorically angled fiber reinforced layers and manufactured using 3D printing technology that demonstrated a ductility up to 29%. The designs enable a gradual load transfer mechanism between different FRP layers demonstrating characteristic load drops and up to 8% strain at failure. Damage in combinatorically angled Glass Fiber Reinforced Polymers (GFRP) composite layers were observed to be mostly sequential compared with the abrupt broom-like failure in high strength FRP composite. 3D printed GFRP composite with Design 4 showed a yield-like plateau leading to a failure strain of 4.2% after reaching its ultimate strength of 260 MPa which is comparable to Grade B steel. The response of a 3D printed high strength GFRP composites was compared with high strength glass FRP composites manufactured using conventional methods. This comparison showed that increase in fiber volume fraction of 3D printer filament can improve mechanical response of resulting composites. This work demonstrates a pathway to manufacture the next generation of structural FRP composite systems with enhanced ductility and inherent mechanism for energy dissipation.