Abstract:A static experiment test and finite element numerical simulation method were carried out to investigate the failure modes and bending performance of multiplanar steel tubular connection with annular ribbed plate. Local axial buckling and transverse plastic deformation failures on such connections were observed from these studies. The local buckling depended on the stress on the chord and the plastic deformation was related to the annular ribbed platetochord model comprised by the annular ribbed plate and a section of chord. For the two failure modes, plastic theory, finite element parametric study and regression analysis were used to develop the proposed formulas of ultimate bending moments for such connections. The proposed formulas were compared with that from experimentations and the results show that the formulas have practical significance and could provide references for the design of similar connections.