Geometric strut optimisation of as-manufactured AlSi10Mg lattice structures for enhanced energy absorption

Purpose The paper aims to evaluate the energy absorption properties of optimised strut cross-section AlSi10Mg lattice structures fabricated by laser powder bed fusion (PBF-LB) additive manufacturing (AM). Quasi-static evaluations indicate a transformation in deformation behaviour of lattices with increasing optimisation which supports strong energy absorption capabilities. Design/methodology/approach The paper applies a novel strut element optimisation method using a hybrid continuum-beam finite element model to improve energy absorption in metal lattice structures. Impact testing occurs on laser powder bed fusion (PBF-LB) fabricated aluminium alloy (AlSi10Mg) lattices specimens to validate the approach. Findings The study provides both a qualitative and quantitative understanding on how PBF-LB AlSi10Mg lattices behave at high strain rates and how strut geometry can be manipulated to produce superior as-manufactured structures. Research limitations/implications The qualification of structures produced by AM is dependent on material, structure and process technology. Further evaluation of geometric and topologic derivatives of the presented structures is required. Practical implications The paper demonstrates the refinement of lattice structures for the use as metamaterials with unique properties unattainable through conventional material science. Social implications The efficient distribution of lattice material reduces unnecessary material expenditure. Structural optimisation provides the means to further reduce expenditure for high value applications such as crash safety and biomedicine. Originality/value This study provides a method to elicit different behaviours and properties in metal lattice structures, which may lead to wide reaching applications as they become more common in engineering industry. It also provides a direct evaluation of mechanical properties of optimised metal lattice structures.