Topology-Dependent Evaluation of Automated Homogenization for Lattice Structures in Aerospace Design

Lattice structures provide significant potential for lightweight aerospace components due to their high stiffness-to-weight ratios and tunable mechanical behavior. However, explicit numerical modeling of large assemblies is computationally expensive, limiting their practical application. To address this, homogenized equivalent solid representations are commonly employed, though the ability of automated homogenization tools to accurately reproduce the mechanical response of different lattice topologies is not yet fully established.

This study evaluates the elastic equivalence of two lattice topologies, simple cubic (SC) and body-centered cubic (BCC), using an automated workflow in ANSYS Material Designer. A 5mm×5mm×5mm representative volume element (RVE) was modeled as a 3D solid element and homogenized to extract effective elastic properties. The equivalent material models were applied to a 100mm×50mm×25mm solid block, while explicit lattice blocks of identical dimensions were generated through periodic replication of the unit cell. Ti-6Al-4V material properties (density 4420 kg/m³, Young’s modulus 112 GPa, Poisson’s ratio 0.35) were used for all the cases.

Mesh convergence studies were conducted for each configuration, and a uniform 0.5 mm mesh was adopted as an optimal compromise between accuracy and computational cost. Displacement-controlled compression up to 2% nominal strain ensured a linear elastic response. Equivalence between explicit lattice and homogenized models was evaluated using total strain energy and stress across twenty incremental load steps.

The results indicate excellent agreement for the SC lattice, with total strain energy and stress deviations of approximately 1.28%, while the BCC lattice exhibits higher deviations of approximately 2.98%. The larger discrepancy for BCC is attributed to its bending-dominated deformation, which is less localized than the axial stretching of SC struts, making it harder for a homogeneous model to capture accurately.

These findings quantify the accuracy of automated homogenization for fundamental lattice topologies, providing engineers with clear, topology-specific error margins for preliminary design of aerospace lattice components.