Flexural capacity and bending stiffness of welded hollow spherical joints with H-beams

Abstract

Eight specimens were designed, and pure bending tests were completed to study the mechanical properties of welded hollow spherical joints (WHS joints) with an H-beam subjected to pure bending. Parametric analyses of the joints under pure bending were conducted in consideration of the diameter(D) and wall thickness (t) of the welded hollow sphere(WHS), and height (h) and width (b) of the H-beam to validate the numerical model. Calculation methods for the flexural capacity and bending stiffness of the H-beam WHS joints were proposed. Results revealed two failure modes of the joints under pure bending, namely, (1) concave at the connection between the WHS and upper flange and external heave at the connection between the WHS and lower flange and (2) small concave at the connection between the WHS and upper flange and tensile fracture of the welding seam at the connection between the WHS and lower flange. The joints demonstrated good ductility under pure bending. The flexural capacity and bending stiffness of the joints were positively related to the wall thickness of the WHS and to the height and width of H-beam but were negatively correlated with the diameter of the WHS. The errors between proposed formulas and FEA for calculating flexural capacity and bending stiffness are very small, indicating the formulas can be employed in structural calculation instead of FEA.