Structural performance and fracture behaviour of additively manufactured AlSi10Mg CHS stub columns

Additively manufactured (AM) aluminium offers geometric flexibility and material efficiency, yet its structural performance remains insufficiently characterized for standard design. This paper investigates the behaviour of PBF-LB/M AlSi10Mg circular hollow sections (CHS) through experimental and numerical analysis. Material response was characterized using tensile coupons across three build orientations (0°, 45°, and 90°) and notched specimens to establish a triaxiality-dependent fracture relationship and develop a fracture model. Stub-column tests with full-field DIC measurements provided benchmarks for finite element (FE) models, which were used for a parametric study on wall thickness effects. The results show that while fracture has negligible impact on peak strength, it significantly reduces post-peak ductility as wall thickness increases in numerically predicted responses. The developed fracture model can be applied to advanced failure analysis of AlSi10Mg structural components. Assessment of current design frameworks reveals that EN 1999-1-1 local buckling provisions are systematically safe but conservative for AM CHS in compression. The findings demonstrate that current design codes for aluminium provide a reliable lower-bound estimate for AM CHS, while the Continuous Strength Method (CSM) offers a more consistent and efficient predictive approach.