Spatial Array Configuration Effect of Body‐Centered Cubic Lattice Structures with Finite Unit Cells

Abstract

The mechanical properties lattice structures have been studied a lot due to the simple geometry. They all follow the assumption that the mechanical properties of lattice structures are identical with the corresponding unit cell. However, our experimental results show obvious boundary effect. In this paper, the spatial array configuration effect (n x , n y , n z ) of body centered cubic (BCC) lattice structures is pronounced to declare the difference. The multilayer BCC lattice structures are divided into three types which show three different deformation mechanism, and their equivalent stiffness will not converge on a unique solution. Then, the “large unit cell” assumption is proposed to theoretically predict the equivalent modulus with different array configuration. Furthermore, the failure modes of the three types are also discussed. The finding results show that the spatial array configuration also plays an important role in determining both the equivalent modulus and the failure modes for the multilayer BCC lattice structures. In addition, we conclude that the name “lattice structure” is more suitable for the current manufacturing level than the “lattice material.”

Numerical investigation of the mechanical properties of lattice structures inspired from polycrystalline materials

“…When compressed, a distinct shear band can be observed along the 45 ○ direction, accompanied by a rapid decrease in stress. 22,23 This phenomenon is quite similar to dislocation slip in metallic single crystals 24 and has prompted researchers to model the microstructure of metals or alloys to design lattice structures. Inspired by the microstructure of triclinic crystal materials, Bian et al 25 introduced twin boundaries into lattice structures, which can improve the energy absorption performance by more than two times.…”