Buckling tests on I‐section steel columns strengthened by additive manufacturing

Wire arc additive manufacturing (WAAM) is a method of metal 3D printing which, when strategically combined with traditional methods of manufacture, has the potential to make a significant impact on the construction sector. To illustrate this potential, an experimental investigation into the flexural buckling response of 13 hot‐rolled I‐section columns, strengthened by WAAM, has been undertaken and is presented herein. The WAAM material was added at the flange tips and distributed non‐uniformly along the member length. Complementary material tests on the conventional and WAAM steels were also carried out. 3D laser scanning was employed to determine the geometry and global geometric imperfections of all specimens, while digital image correlation measurements were taken to provide a detailed insight into the surface deformation characteristics of the specimens during testing. The beneficial effects of the WAAM stiffeners were an increased cross‐sectional area and second moment of area, enhanced local buckling capacity and a more favourable residual stress pattern. Increases in axial capacity of between 17% and 54% for increases of mass between 2% and 26% were achieved, highlighting the tremendous potential in terms of structural efficiency and material savings that can be realised by the combination of WAAM with traditional manufacturing methods.