Flexural Properties of Additively Manufactured Structures Reinforced with Cellular and Fractal Patterns

The interest in exploring new microarchitected materials that take advantage of precise geometrical construction to achieve unique properties has recently arisen due to the accelerated development of additive manufacturing. Exploring and understanding the mechanical behavior of additively manufactured structures remains crucial to expand the capabilities of this technology. Herein, a methodology to design, fabricate, and characterize the flexural behavior of additively manufactured structures reinforced with cellular and fractal patterns is presented. A total of 16 different arrangements are designed, tested, and numerically simulated, including 4 cellular arrangements, 10 fractal, and 2 nonreinforced structures. Samples are fabricated out of polylactic acid via material extrusion, subjected to three-point bending loading and simulated via finite element models. Further, the fracture modes and deformation mechanisms from the experimental tests to obtain a broad overview of their flexural capabilities are examined. An increase in stiffness of up to 36% is observed for the cellular-reinforced structures, while the fractal-reinforced structures present great recovery, flexibility, and unconventional bending behaviors. Cellular- and fractal-reinforced structures are designed, simulated, and tested under three-point bending. The structures reinforced with cellular patterns are stiffer than the fractal-reinforced structures but cannot withstand large deformations before fracture. The effective flexural properties, deformation, and fracture modes of the structured materials can be tuned through geometrical configurations.image (c) 2024 WILEY-VCH GmbH