Self-adaptive pinned 3D lattice for curved sandwich structures

The design and fabrication of curved sandwich structures with a 3D lattice core always faces the challenge of adaptability and connectivity between the core and the skins. Here, we propose a pinned method by releasing rotational degrees of freedom in the common node of the adjacent lattice cells. The design of the lattice core only needs to consider the size and number of cells and is independent of the shape of the skins. The pinned design demonstrates advantages in self-adaption of the 3D lattice core to skins with generalized cylindrical type and ensures to fabricate curved sandwich structures of a large scale. Lattice samples of four kinds of node-connection forms with three different strut thicknesses are fabricated to investigate the effects of pin-joint design and strut thickness on mechanical performance. Lattices with suitable collinear connection design have comparable modulus and strength to snap-fitted lattices. The proposed method has the potential for standardized production of curved 3D lattice sandwich structures with excellent mechanical performance. • We propose a pinned method by releasing rotational degrees of freedom in the common node of the adjacent lattice cells. • The pinned design demonstrates advantages in self-adaption of the 3D lattice core to skins with generalized cylindrical type and ensures to fabricate curved sandwich structures of a large scale and can be extended to various techniques. • Lattices with suitable collinear connection design have comparable dimensionless modulus and strength to snap-fitted lattices.