Lattice-based thin-walled lenticular deployable composite boom via 3D printing of continuous fiber reinforced thermoplastic matrix composite

Thin-walled lenticular deployable composite booms (DCBs) are widely used in space deployable arms that require folding, storage, and load-bearing during deployment. However, space deployable structures have complex multi-directional mechanical performance requirements, which place higher demands on the elastic properties of DCBs in various directions. Therefore, this paper proposes a lattice-based 3D printing strategy to form DCBs, achieving lightweight design while also considering the multi-directional elastic properties of the DCBs. First, the cross-sectional and surface lattice structure of the DCB were designed, and the mechanical behaviors of radial flattening, folding, bending resistance, and axial compression were evaluated using numerical calculations and experimental methods. The study found that the directional elastic properties of the DCB could be adjusted by changing the line spacing (L). Compared to the closed structure, after lattice structuring (when L = 4.8 mm), the folding and bearing stiffness decreased by approximately 90.0 % and 60.0 %, respectively; however, the specific stiffness under loading is still improved. The consistency of the force-displacement curves of the three-point bending test and cantilever beam test before and after the folding cycle of the DCB indicates that both the flattening and folding of the structure are elastic deformations. In summary, lattice-based DCBs are expected to provide new design ideas and solutions for the engineering development of space deployable arms.