Study on compressive bearing capacity and axial stiffness of welded hollow spherical joints with H-shaped steel member

Abstract

To study the compressive bearing capacity and stiffness of welded hollow spherical joints with H-shaped steel member(WHS-HSM joints), axial compression test was conducted on eight specimens of WHS-HSM joints. By verifying the correctness of the numerical model, the parametric analyses were done considering the following factors, such as the welded hollow sphere diameter (D), the wall thickness of the welded hollow sphere (t), and the height (h) and width (b) of the H-shaped steel member(HSM). The calculation methods of the compressive capacity and axial stiffness of WHS-HSM were proposed. The results show that the failure mode of the joints under axial compressive load is the hollow sphere’s concave failure starting from the flange edge of H-beam. Under axial compressive load, the joints show good ductility. The bearing capacity and initial axial stiffness of the joints are positively related with the wall thickness of the welded hollow sphere (t), the section height(h) and width(b) of HSM, but are negatively correlated with the diameter(D) of the welded hollow sphere. The formulas for calculating the compressive bearing capacity and initial axial stiffness proposed in this paper have high accuracy.