Structural Analysis Of UHV Transmission Steel Tubular Tower Considering Joint Rigidity

Owing to the advances in technique and economy efficiency, the steel tubular towers are widely applied in ultra-high voltage(UHV) transmission line.In order to facilitate the manufacture and installation, the bracing members, the horizontal members and the primary members are connected by gusset plates, and the mechanical properties of gusset plate joints are not only different from rigid connections but also different from hinges joint, which are semi-rigid. However, the semi-rigid joints are always treated as ideal rigid connections or hinge joints when analysing the structure of UHV tublar towers, which is uncoordinated to the practical engineering.Therefore, studying the calculation method of gusset plate joint rigidity and its influence on UHV steel tubular tower structural analysis contributes to being more accurate for UHV steel tower structural analysis,what's more, it also can improve the the design level.In this paper, the parameterized finite element model of the C- gusset plate joint was established upon the parameterized geometric model, furthermore, the joint stiffness including axial stiffness, in-plane bending rigidity and out-of-plane bending rigidity was defined, and, the impact of these parameters like the diameter of main member, the diameter-thickness ratio of main member, the diameter ratio of main and bracing member, the angel between main and bracing member, the thickness ratio of bracing and main member, the thickness ratio of gusset plate and main member on the joint stiffness is analyzed, on the basis of which, computational formula of joint stiffness was achieved by multielement non-linear regression(MNLR).Then the semi-rigid node elements were used to simulate the semi-rigidity of joints in the UHV steel tubular tower. In this foundation, the finite element model of the UHV steel tubular tower was created including semi-rigid node elements. Further, the influence of joint stiffness on the displacements of conductors and shield wires hanging points, the internal force of members and the bend of members was researched. As shown in the results, the joint stiffness has a significant effect on the displacements of conductors and shield wires hanging points, the internal force of horizontal members, the internal force of bracing members and the bend of main members. The affection on the internal force of main mebers on the tower head lesser, the internal force of main mebers on tower legs the least.