Effects of Unit Cell Size on the Mechanical Performance of Additive Manufactured Lattice Structures

Abstract

Lattice structures are generated through the repetition of smaller structures, defined as unit cells. These structures are popular alternatives for bone implants due to the potential to adjust the stiffness. However, in some applications, there are volume and mass constraints that cannot be exceeded. Therefore, to match the lattice structure’s stiffness to that of the natural bone, unit cell sizes should be altered. In this study, the effects of different unit cell sizes, on the compression behavior of lattice structures fabricated from 316L stainless steel (SS) via laser beam powder bed fusion (LB-PBF) are studied through finite element analysis (FEA) while the volume and mass are kept constant and results of which, are validated by experiments. It was found that energy absorption capability and stiffness of lattice structures can increase with decreasing the size while the volume and mass are kept constant. The lattice structure with smaller unit cell dimensions tolerated a relatively higher maximum force for the same amount of displacement.