Testing and analysis of additively manufactured aluminium I- and C-section stub columns

Laser beam powder bed fusion (PBF-LB/M) has become more prevalent in recent years, favoured for its ability to produce intricate geometries with high dimensional accuracy. Aluminium alloys are widely applied in the aerospace, automotive and construction industries owing to their high strength-to-weight ratios, good durability, corrosion resistance and ease of fabrication. To date, there is, however, a dearth of experimental data relating to the structural performance of PBF-LB/M aluminium elements, which is preventing the wider adoption of this technology in construction applications. To address this gap, an experimental investigation into the mechanical properties and structural performance of the PBF-LB/M AlSi10Mg I- and C-section stub columns has been conducted and is presented in this paper. Seven I-section and seven C-section stub columns were tested under axial compression. The geometric dimensions and the local imperfections of the test specimens were measured using 3D laser scanning. Digital image correlation (DIC) was employed to capture the surface deformation field during testing. In the present paper, following a description of the specimen manufacture, the experimental programme is described, the test results are analysed and the applicability of EN 1999-1-1:2023 (EC9), the Aluminum Design Manual 2020 (ADM), the Direct Strength Method (DSM) and the Continuous Strength Method (CSM) to the design of PBF-LB/M aluminium I- and C-sections is assessed by comparing the test results with the associated design predictions. The performances of the PBF-LB/M aluminium I- and C-sections were found generally to align with the trend of the conventionally-manufactured aluminium I- and C-sections. All of the four design approaches yield safe-sided resistance predictions, among which the CSM provides the most accurate predictions by accounting for the effects of strain hardening in the PBF-LB/M aluminium. The experimental results provide valuable benchmark data for additively manufactured aluminium structural cross-sections and demonstrate that the existing aluminium design methods can be safely extended to predict the cross-sectional resistance of PBF-LB/M AlSi10Mg I- and C-sections in compression. • Coupon tests conducted to obtain the mechanical properties of PBF-LB/M AlSi10Mg material. • 3D laser scanning and characterisation of local imperfections of PBF-LB/M I- and C-sections. • Experimental study on local buckling behaviour of PBF-LB/M aluminium I- and C-sections. • Applicability of design approaches in EC9, ADM, DSM and CSM assessed using test data.