Improving stiffness and strength of body-centered cubic lattices with an I-shape beam cross-section

Abstract

The stiffness and strength of body-centered cubic (BCC) lattices are greatly improved by utilizing an I-shape beam cross-section. First, a cross-sectional analysis is performed to demonstrate the improved bending stiffness of the I-shape beams compared with the beams with a circular cross-section. Then, a novel multiscale modeling approach is employed to compute the effective stiffness of the lattices and investigate the stress distribution under a compressive load. The designed lattices are fabricated by selective laser sintering (SLS) and the compression tests are carried out. The results show that the proposed I-shape cross-section significantly improves the stiffness and strength of the BCC lattices. The improvement of the stiffness and strength with different beam slenderness ratios are also investigated. The maximum improvement of the stiffness–weight and strength–weight ratio is 159.13% and 41.42%, respectively. In addition, nonlinear finite element analysis (FEA) is carried out to investigate the mechanisms of improved material properties by different cross-sections. The newly proposed BCC lattices provide a potential alternative to conventional BCC lattices with enhanced stiffness and strength.