Mechanical properties and shape memory effect of 4D printed cellular structure composite with a novel continuous fiber-reinforced printing path

Herein, a printing strategy was proposed and expended, which allows fabricating diverse geometries of cellular continuous fiber-reinforced composites (CFRCs) with fiber distribution and interlacement in the cellular structure uniformly. A class of printed triangle-filled cellular structure composites was prepared to present the detail of the printing strategy. The effects of printing and structural parameters on the mechanical properties, as well as shape memory performance of printed CFRCs, were studied precisely, and thereafter, a Finite Element (FE) model was developed on the basis of the printing path to stimulate and analyze the tensile process. Experimental results showed that introducing only 3.8% fiber content into the composite can significantly improve the tensile strength by more than 300%. An increment of cell length was capable of strengthening tensile features compellingly due to changing orientation and alignment degree of fiber in the structure. By contrast, sizing the cell length and embedding further fiber have represented a reverse pattern against the composite's shape recovery ratio, which witnessed an adverse impact on shape-changing materials. A conclusion was given that the mechanical properties and shape memory effect of the 3D-printed continuous fiber-reinforced composite can be optimized by adjusting the geometric parameters and fiber content. [Display omitted] •Evenly distributing fibers in continuous fiber-reinforced cellular structure composites by a unique 3D printing method.•Investigating the role of printing and structural parameters on the mechanical properties and shape memory performance.•The tensile failure mode of continuous fiber-reinforced cellular structure composites was analyzed.•The feature of the fiber-reinforced composite can be optimized by regulating the cellular structures.