Comparative analysis of different lattice topologies for cellular structure optimization in additive manufacturing

Abstract

Cellular structures are prominent over solid structures in Additive manufacturing because of their inherent features like reduced weight, more strength, and porosity. A cylindrical component was designed and then different lattice topologies like grid, vin tile and hexagon were used to create the internal cellular structure. A comparative analysis was then carried out on these cellular structures based on different unit cell sizes, variable strut thickness, coefficient of volume reduction (VRC) and surface area coefficient (SAC). The effect of these parameters on mechanical properties was studied and correlated. These different cellular structures were then fabricated using PLA (Polylactic acid) material on a Makerbot Replicator + 3-D printer. These cellular structures were then simulated through FEA by providing loading and boundary conditions and the results were then evaluated and validated with experimentation work. The yielded results shown lowest stress and smallest of the deformation for vin tile lattice structure as compared to grid and hexagon lattice cellular structures. Physical experimentation results also validated the simulation outputs. This study was not limited to only creation of different cellular structures but it also compared how the structures behave mechanically through unit cell parameters like VRC and SAC. The cellular structures were tested virtually using FEA and physical experimentation was carried out on the 3-d printed samples. The results obtained through both the tests confirmed that vin tile cellular structure bears less stress and lowest deformation as compared to grid and hexagon cellular structures when subjected to same compressive loading conditions.