2026-10-09T23:01:27Z https://api.figshare.com/v2/oai

oai:figshare.com:article/34021290 2026-09-29T04:54:53Z category_32963 category_33398 portal_1005 item_type_6 month_year_09_2026

Process-structure interactions in stretching-dominated lattices: how nodal toolpath fragmentation limits geometric isotropy in MEX-AM F Mirza (25135290) S Shenoy Baloor (25135293) S Nunna (15776759) C Ramanath Kini (25135296) Claudia Creighton (13064505) Engineering Manufacturing engineering Science & Technology Technology Engineering, Manufacturing Materials Science, Multidisciplinary Engineering Materials Science Fused deposition modelling (FDM) Polylactic acid (PLA) Mechanical metamaterials Cellular structures Process-structure interaction Nodal Toolpath Fragmentation (NTF) PLA Stretching-dominated lattice metamaterials offer exceptional stiffness-to-weight efficiency, but their physical realisation via material extrusion additive manufacturing (MEX-AM) is fundamentally constrained by process-induced defects. This study investigates these process-structure interactions by evaluating Isomax (cubic + octet) architectures. An initial simulation-led framework evaluated Isomax against Kagome topologies, leading to the exclusion of the buckling-prone Kagome from physical testing. Closed-cell Isomax specimens were subsequently fabricated in PLA and evaluated under tension, flexure, and compression. Mechanical testing revealed severe performance asymmetry. Tensile and flexural strengths degraded by > 60% and ~ 74%, respectively, versus solid controls. Fractography suggests this penalty is associated with Nodal Toolpath Fragmentation (NTF), a slicer-induced discretization of the extrusion path at structural intersections that forces premature, interface-dominated failure. Conversely, compression physically suppresses NTF via contact stabilisation. This yields near-isotropic behaviour, with orientation-dependent strength varying by only 1.4%, and limits the compressive manufacturing penalty to 14% relative to numerical baselines. This confirms geometry dictates compressive performance, while process defects govern tension. Deploying Maxwell-stable metamaterials requires process-aware design prioritising toolpath continuity. By isolating these bottlenecks, this work supports UN Sustainable Development Goals 9 and 12, optimising material efficiency for load-bearing structures. 2026-01-01T00:00:00Z Text Journal contribution 10.26187/deakin.34021290 https://figshare.com/articles/journal_contribution/Process-structure_interactions_in_stretching-dominated_lattices_how_nodal_toolpath_fragmentation_limits_geometric_isotropy_in_MEX-AM/34021290 CC BY 4.0