Effect of strut length and orientation on elastic mechanical response of modified body-centered cubic lattice structures

Abstract

Lattice structures (LSs) have been exploited for wide range of applications including mechanical, thermal, and biomedical structures because of their unique attributes combining the light weight and high strength. The main goal of this research is to investigate the effect of strut length and orientation on the mechanical characteristics of modified body-centered cubic (BCC) LS subjected to a quasi-static axial compressive loading within linear elastic limit using finite element analysis. In this study, two sets of LS were built and analyzed in commercial finite element software, ABAQUS/CAE/EXPLICIT 6.16, using a “smart procedure,” which was developed for this research to reduce the computational time and increase the accuracy of results by creating hexahedral mesh elements. The first set comprises 13 models having fixed strut length with strut angle variation from 40° to 100° with a step of 5°. The second set also includes 13 models; however, having variant strut length, kept constant for a single unit cell and through the entire model but varied from one model to another, with the same strut angle variation as the first set. In addition, the BCC LS with a strut angle of 70.53° was replicated in both sets because it was considered as a reference model to compare the results with it. Furthermore, specimens of the reference model were fabricated by a fused deposition modeling- (FDM) based 3D printer using acrylonitrile butadiene styrene (ABS) material and tested experimentally under compression. Experimental results are observed to be in good agreement with those of the finite element simulation, hence the same loading and boundary conditions were adopted for all other models. It was observed that the fixed strut length BCC LS with a strut angle of 100° offers the highest modulus. However, the highest specific strain energy absorption and specific stiffness as well as the least value of weight were dictated by a variant strut length BCC LS with a strut angle of 40°.