Direct Nonlinear Analysis Of UHV Transmission Lines Tower Considering Joint Slippage

UHV transmission tower is tipical high-rise steel structure, ant its voltage grade increased gradually. In order to meet the requirements of the electrical safe distance, the length of members in transmission tower are becoming longer, spatial scale became more and more big, the whole tower more and more flexible, the deformation of UHV transmission tower becomes larger and larger under external loading, eventually leading to the two order effect more significantly. Even more, the bloted joint slippage further increased the deformation of transmission tower.Because of its limitations, the traditional design method of the tower fails to account for the effect of the two order effects after the structural stress, so that the equilibrium equations are based on the components that have no deformation, wich leading to the deviation of the calculation results, and finally the calculation results can not meet the reasonable requirements of the design.Therefore, it is need for direct nonlinear analysis of UHV transmission tower.Based on the nonlinear analysis and design method on the existing research, in this paper we use the direct nonlinear analysis that ynthetically considering geometric and material nonlinear, residual stress analysis method, the initial defects, the node connection slippage of UHV transmission tower. The load displacement curve of the bolt is obtained by the experiment, and based on the experimental results, the slip models are modified in the different nodes. According to the ZMP2 type of the 1000 k V UHV angle steel tower, we studied the influence of bolt slip on UHV transmission tower using the direct nonlinear analysis method. Through the comparison of the direct nonlinear analysis and the traditional linear analysis, the influence of different calculation methods on the axial force, displacement of the joint, the whole deformation of the tower and the failure location of the tower are studied.We can get chat the advantage of node connecting the slip of UHV transmission tower direct nonlinear and analysis of design method of reasonable consideration, which has an important theoretical guidance to the safety, economy and UHV transmission tower design concept.