Engineering hollow-strut lattice nodes for enhanced load-bearing with cubic symmetry

Abstract

• Novel advanced nodal architectures are embedded within hollow-strut lattices. • These nodal designs strengthen all three orthogonal axes with cubic symmetry. • Mechanical properties are enhanced up to 153% with advanced nodes. • Nodal designs shift fracture from node-based to strut-based failure modes. Metallic hollow-strut lattices (HSLs) offer a promising pathway toward lightweight, multifunctional materials. Their structural application, however, has been hindered by vulnerabilities centralised at their nodes, where stress concentrations trigger premature failure. Conventional approaches reinforce nodes to resist loads in a single direction, compromising overall mechanical integrity. Here, we introduce two novel internal nodal architectures—multi-level and multi-topology—designed to deliver uniform strengthening along all three orthogonal axes (cubic symmetry). Fabricated in AlSi10Mg via laser-based powder bed fusion (PBF-LB), these architectures redistribute stress, eliminate weak hollow nodes, and fundamentally alter the HSL failure mode by shifting fracture from nodal rupture to strut buckling. This transition renders fracture pathways predictable rather than stochastic and facilitates post-failure stress recovery. When implemented in HSLs with struts aligned to the compressive load, the elastic modulus increases by up to 153%, yield strength by 114%, and ultimate compressive strength by 119%, with only a 48% density increase. These improvements were highly consistent across all orthogonal axes, confirming strong cubic symmetry. HSLs with inclined struts show notable gains as well, with 62% higher modulus, 74% higher yield strength, and 73% greater compressive strength at just 32% added density. These advances establish a new framework for engineering high-performance, tunable HSL metamaterials with enhanced load-bearing capacity and reliability.

Topics & Concepts