Compressive Strength Evaluation of 3D Printing Infill Patterns Designed with Strut Lattices

Lattice structures have emerged as an effective strategy in additive manufacturing to achieve lightweight components with tailored mechanical performance. This study investigates the compressive behaviour of three strut-based lattice configurations—Body-Centered Cubic (BCC), Diamond, and Face-Centered Cubic (FCC)—fabricated using Fused Deposition Modelling (FDM) with Polylactic Acid (PLA). The lattice geometries were modelled in SolidWorks, produced under consistent printing parameters, and evaluated through both Finite Element Analysis (FEA) and experimental compression testing in accordance with ASTM D695. FEA was performed using ANSYS to assess deformation, stress distribution, and strain under a 20,000 N compressive load, while physical testing validated these predictions and identified failure mechanisms. The results show that the FCC lattice provided the highest experimental compressive strength due to its reduced air gaps and improved structural continuity, followed by the Diamond structure with balanced strength and ductility. The BCC lattice demonstrated the lowest strength but exhibited significant deformation capacity suitable for energy-absorbing applications. Discrepancies between simulation and experiment were attributed to FDM-related imperfections such as strut inaccuracies and thermal shrinkage. Overall, the findings highlight the critical influence of lattice topology on mechanical performance and provide guidance for optimizing lightweight structures in additive manufacturing applications.