Mechanical properties of a new type of plate–lattice structures

Abstract

In this study, a new type of lattice structure, namely plate–lattice, was investigated. The plate–lattice structure was constructed by placing a plate between two adjacent trusses. Theoretical analysis of Young's modulus on a simple cubic–truss and cubic–plate revealed that the Young's modulus of the plate–lattice was twice that of the lattice composed of trusses. Subsequently, further studies on more complex structures, such as octet–trusses and octet–plates, were conducted using the finite element method (FEM). Furthermore, the periodic boundary condition (PBC) was applied to a unit cell to reflect the response of an infinite structure. Additionally, equivalent Young's modulus, strength, and shear modulus were compared at the same density. The results indicated that the stiffness of the plate–lattices was more likely to realize the Hashin–Shtrikman theoretical upper bounds. The plate–lattice structure exhibited 2–3 times higher stiffness values, including Young's modulus and shear modulus, than those of the truss lattice structure. Furthermore, the Ashby charts of relative compressive modulus (E/Es) and relative strength (σ/σy) were plotted as a function of relative density, and the data indicated that the plate–lattice structure was a new low density structure, which could utilize materials to the maximum extent.