Geometrical characteristics and axial compression performance of stainless steel tubular stub columns fabricated by wire and arc additive manufacturing
In order to study the mechanical properties of wire and arc additive manufacturing(WAAM)stainless steel components,a group of tubular stub columns with different diameters,heights and wall thicknesses were fabricated by WAAM technology,and the basic mechanical properties of 316L stainless steel were obtained by tensile tests of standard specimens.Geometric measurements were carried out with 3D laser scanning to determine their geometric parameters and local imperfections.Through the compression test of stub columns,the failure mode was obtained and compared with the local geometric imperfection shapes.The load-end axial displacement curves were then obtained,and the axial compression capacity and the related influencing factors were analyzed.The test results of axial compression capacity were compared with the predictions from various steel structure design codes.The results show that compared with the conventional steel tubes,the tubular stub columns by WAAM have more dimension variations in the cross-section and larger local geometrical imperfections,and the average and maximum of the maximum imperfection deviations are 0.27-0.75 mm and 0.33-0.95 mm.Local buckling occurs in all tubular stub columns in the compression capacity tests,and the buckling region is close to the region with large local geometrical imperfections.The normalized axial compressive loading of tubular stub columns by WAAM ranges from 0.88 to 1.06.Generally speaking,the corresponding axial compression capacity decreases with the increase of the slenderness ratio,and the local geometric imperfections have a certain influence on the ultimate capacity.The tubular stub columns by WAAM can satisfy the ultimate capacity requirements of European code EN-1993-1-4 and American code AISC 370,while most specimens fail to meet the design axial compression capacity requirements of the Chinese Code DL/T 5154-2002.
tubular stub columnstainless steelwire and arc additive manufacturinggeometrical measurementcompression performance