Mechanical performance of carbon fiber‐reinforced polymer cellular structures manufactured via fused filament fabrication

This article investigates the mechanical behavior of polyamide and carbon fiber‐reinforced (CFR) polyamide structures produced by Fused Filament Fabrication. CFR improves solid polyamide's tensile strength and modulus by more than 200% and 800%, respectively. The enhancement is highest in the parallel raster due to the alignment of the fibers in the printing direction. The compression tests of gyroid, honeycomb, and Voronoi cellular structures revealed the effect of geometry and fiber reinforcement on energy absorption performance. CFR gyroid infill offers the best performance with a specific energy absorption capacity reaching 10 kJ/kg and an efficiency close to 50%. Fiber reinforcement improves energy absorption by a factor of four or higher while increasing the weight by only 10%. The energy absorption capacity of the reinforced polyamide offers enormous potential for developing new lightweight load‐bearing and impact‐absorbing structures. The tensile strength of fused filament fabrication‐based 3D printed tensile specimens was improved by carbon‐fiber reinforcement. Fiber reinforcement also improves the impact energy absorption performance of honeycomb structures. Snapshots of polyamide and carbon fiber‐reinforced polyamide honeycombs under compression provide insight into the deformation behavior.