Compressive mechanical properties of layer hybrid lattice structures fabricated by laser powder bed fusion technique

Abstract

A layered hybrid lattice structure consisting of a body-centered cubic (BCC) structure and an N-type structure with a negative Poisson's ratio effect is designed. In order to assess the effect of the position and number of N-type structure layers in the overall lattice structure on the mechanical properties, three kinds of hybrid lattice structures with different positions and numbers of N-structure layers are manufactured by using laser powder bed fusion (LPBF) technique. Compression experiments are carried out on the three kinds of layered hybrid lattice structures and the BCC lattice structure for comparisons. The entire loading process is recorded and the deformation pattern of the lattice structure is captured. The experimental results show that the presence of the N-type structure has a significant effect on the deformation pattern of the lattice structure. Comparing the mechanical response and energy absorption efficiency, it is found that the hybrid lattice structure performs better than the BCC structure when the structural strain is small. In addition, finite element models of the N-type structure unit-cell and hybrid lattice structures are established. Numerical simulations are conducted to verify the negative Poisson's ratio behavior of the N-structure and predict the deformation modes of the layered hybrid lattice structure.