Shear Deformation Response for Three-Dimensional Lattice Structures : 1st Report, Effects of Geometry of Overall Lattice Structure

Abstract

In this paper, the shear response of three-dimensional lattice structure was investigated based on numerical stress analysis, FEM. In particular, effects of number of unit cells in three directions on the mechanical properties (shear modulus G^* and collapse strength τ^*) of lattice structures were discussed based on theoretical analysis and FEM. It is found that the mechanical properties strongly depend on the number of unit cell in three directions x, y, z, and for a flat structure (N_y=1), the deformation pattern in the structure can be classified into two types. The shear modulus G^* for a flat structure obtained by FEM can be estimated by the elementary beam theory with a good accuracy. Also, for a flat structure with slender struts, the collapse is occurred by elastic buckling, and that with relatively thicker struts, the collapse strength agrees well with the theoretical result. Moreover, the cubic structure having the same number of unit cell in x and z directions (N_x=N_z=N) shows a unit curve for the shear modulus G^*, so that the modulus can be estimated by the curve for various cubic structures.