Mechanical characterization and deformation behaviour of polymer-based lattice structures fabricated via fused deposition modelling

Lattice structures fabricated using additive manufacturing have gained significant attention due to their ability to achieve lightweight designs with enhanced mechanical performance. In this study, a comparative investigation was carried out on two different lattice geometries, namely Structure A (Re-entrant Hexagon structure) and Structure B (star triangular re-entrant structure), fabricated using Fused Deposition Modelling (FDM) with PLA and ABS filament. The design was validated through FEA using ABAQUS from the reference study. The obtained deformation patterns and stress distributions showed good agreement with those reported in the reference study. Although auxetic deformation is governed by geometry, its mechanical performance is significantly influenced by material properties and manufacturing parameters. Compression tests were conducted using a Universal Testing Machine to evaluate their deformation characteristics and compressive performance. Among the tested specimens, PLA exhibited a maximum compressive stress of approximately 3.2 MPa compared to 2.3 MPa for ABS, while Structure A and Structure B achieved peak compressive stresses of approximately 28 MPa and 32 MPa, respectively. This study systematically investigates the influence of auxetic geometry and material selection on the compressive behaviour of FDM-fabricated lattice structures through multi-specimen experimental testing and finite element simulations, with quantitative comparison between experimental and numerical responses.The findings provide valuable insights for designing optimized PLA lattice structures A for Lightweight structural panels (aerospace/automotive), drone frame components, Robotic arms & fixtures, and ABS for Automotive interior components & Protective housings (electronics casing), and structure B of PLA and ABS for Packaging structures (fragile items protection), Automotive crash absorbers (crumple zones), Helmet liners & protective gear.