Experimental and numerical investigation on the rotational resistance behavior of aluminum alloy insert hub joints

Aluminum alloy insert hub (AAIH) joints provide a cost-effective and efficient solution for aluminum alloy space latticed structures composed of circular hollow section (CHS) members, utilizing mechanical meshing between serrations and matching slots. Three-point bending tests were conducted to investigate the rotational resistance behavior of AAIH joints. The failure modes along the major and minor axes were identified as local buckling on the compression side of the tube's transition zone and rigid rotation of the tubes around the hub, respectively. The P-w curves revealed that AAIH joints exhibit semi-rigid behavior and significant post-buckling capacity in the major axis direction, whereas behaving nearly as hinged connections in the minor axis direction. The P-ε curves indicated that large deformations were primarily concentrated in the tube's transition zone, with negligible axial force in the tubes during testing. Finite element (FE) models of AAIH joints were subsequently developed using the ANSYS and validated against experimental results in terms of deformation process, ultimate load, and M-φ curves. Furthermore, the M-φ curves of AAIH joints were obtained, and the deformation and stress distribution in the joint zone were analyzed via numerical simulation. Finally, the influence of two gap characteristics between the serrations and slots on the M-φ curves was further investigated.