Shape recovery and energy absorption properties of 3D printed continuous ramie fiber reinforced thin‐walled biocomposite structures

AbstractContinuous fiber reinforced composites are widely used in thin‐walled structures due to their high specific strength and stiffness. In this work, continuous natural fiber was introduced into thin‐walled biocomposite structures via 3D printing technique to enhance energy absorbing properties and promote ecological compatibility. The effects of varying configurations of printing speed, layer thickness, and path optimization on the deposition quality of continuous ramie fiber and polylactic acid matrix were explored. The results showed that reduced printing speed (100 mm/min) and optimal layer thickness (0.25 mm) effectively minimized structural forming defects. In addition, further enhancements in the printing quality could be achieved by smoothing the path with rounded corners. Based on optimal printing strategies, different configurations of thin‐walled biocomposite structures were fabricated. Lateral monotonic and cyclic load tests were performed to investigate their energy absorption and shape recovery capacities. When the loading displacement was 10 mm (strain was 20%), the circular structure presented good shape recovery capability, with measured recovery ratio remaining above 89%. The hexagonal structure showed a similar variation in shape recovery ratio as the quadrangular structure, both remaining above 75%. Moreover, the specific energy absorption of all the structures converged after two cycles, indicating their remarkable and stable repeatable load‐bearing capacity.Highlights Continuous ramie fiber reinforced thin‐walled structures were prepared. The deformation patterns of structures under lateral compression were analyzed. Energy absorption and shape recovery radio were studied under cycle loading. Printed structures exhibited great and stable repeatable load‐bearing capacity.