The Mechanical Model And Analysis Of UHV Suspension Cable Guyed Tower

Due to the advantages of transmission capacity and high transmission efficiency,the Ultra High Vacuum(UHV) transmission line is being increasingly widely used and its security cannot be ignored. In traditional mechanical models, the analysis of tower's joint is simply assumed rigid joint or hinge-joint or beam-truss model. However, the connection of the UHV transmission tower is a kind of semi-rigid joint between pinned and rigid connection. Although the beam-truss model can consider the semi-rigid, it is just a qualitative analysis, not a quantitative analysis.Simultaneously, in angle transmission tower the main leg angle member and inclined angle member are connected eccentrically by bolts, however, the traditional analysis models assumed both of main angle member and inclined angle member are connected by their centroid directly. The traditional analysis model also ignored the influence of eccentric distance. These simplifications are clearly unreasonable. This paper's purpose is to research the mechanical model and analysis of the ±800kV suspension cable guyed tower. It is pretty vital to establish a reasonable finite-element model to analyze the Suspension cable guyed tower.Based on the above considerations, this paper ready to pose an improved finite element model on the basis of beam model, which can consider the joint's rotational stiffness and the eccentricity in the transmission tower, then provide reference for practical engineering calculation and analysis. Therefore, this paper has done the following work:(1) Introducing the objectives, contents and test programs of full-scale testing of suspension cable guyed tower. A refined shell element model was established. There was a comparison between the new refined shell element model's strain calculation results with the full-scale testing data of suspension cable guyed tower under the windless conditions and normal 90 degree wind conditions. The results showed that the refined shell element model can simulate the members' strain variation rules with the change of load levels. In addition, the refined shell element model's simulation results agree well with the experimental results.(2) The traditional beam element model was established. Comparing the traditional beam element model and the new refined shell element model's strain calculation results with the full-scale testing data of suspension cable guyed tower under the windless conditions and normal 90 degree wind conditions. The results showed that the simulation results of refined shell element model are better than traditional beam element model's.There is a relatively large simulation error of inclined angle member's strain in traditional beam element model.(3) Introducing the implementation of suspension cable guyed tower's semi-rigid joint and the simulation approach of connection eccentricity. Combining the advantages of traditional beam element model and the new refined shell element model, then posed an improved finite-element analysis model, which can consider the joint semi-rigid and the eccentricity produced by the connection between inclined angle member and main leg angle member. Then this paper compared the traditional beam element model, the new refined shell element model and the new improved model's strain calculation results with the full-scale testing data of suspension cable guyed tower under the normal 90 degree wind conditions. The results showed that the three models can simulate the members' strain variation rules with the change of load levels.The simulation error of inclined angle member's strain in traditional beam element model is relatively large. The refined shell element model and new improved model's calculation results agree well with the experimental results.