Ultimate tensile and compressive performances of welded hollow spherical joints with H-beam

Welded hollow spherical joints with H-beam are a new type of spatial grid structural joints. Experiments and numerical simulation were conducted to investigate the axial tensile and axial compressive performances of the welded hollow spherical joints with H-beam. The influences of material strength, size of joint, and stiffening rib on the mechanical properties, were analyzed. The formulas were proposed to calculate the bearing capacity under axial tension and compression. The major conclusions are as follows: (1) Welded hollow spherical joints with H-beam developed strength fracture under axial tensile load, and hollow spheres developed buckling failure under axial compressive load. The failure mode was related to the strength of the material. (2) Proper arrangement of stiffening ribs can increase bearing capacity of welded hollow spherical joints with H-beam. The improvement coefficients were 1.1 under axial tension and 1.4 under axial compression. (3) The compression bearing capacity of welded hollow spherical joints with H-beam increased with the increase in height and flange width of H-beam, as well as wall thickness of the hollow spheres, but it decreased with the increase in diameter of hollow spheres. (4) The formula used to calculate tensile bearing capacity of welded hollow spherical joints with H-beam was proposed according to the punching shear model. (5) The design formula of compressive bearing capacity of welded hollow spherical joint with H-beam was obtained through the linear regression of abundant numerical simulation data.