Investigation On Equivalent Static Wind Load Of Lattice Towers And Transmission Tower-line System

Transmission tower-line system is extremely sensitive to wind load for it's large span,high and flexibility structural characteristics.The randomness of the wind load itself and the coupling effect between the tower and lines make it difficult to research the tower-line system.Many experts and scholars are doing research on the transmission tower-line system,and have got a lot of valuable results,but there are still many problems to be solved.Based on the existing research,this thesis establishes the internal force equivalent static wind load analysis method of the transmission tower and the transmission tower-line system based on the internal force equivalent,using the simplified model of the transmission tower system and the wind tunnel test data.The main contents of this thesis are as follows:1.The finite element model of the transmission tower system is simplified,the mode of simplified model is obtained by using the method of eigenvalue analysis and is compared to the mode of finite element model.2.The generalized wind loads of the transmission tower in the along-wind direction,the cross-wind direction and the torsion direction are analyzed based on the transmission tower high frequency force balance wind tunnel test.Through the transmission aero-elastic model wind tunnel test,the changing trend of transmission line's tension with wind speed under wind load.3.The wind load spectrum along the tower's height is derived by using the generalized load spectrum from the transmission tower high frequency force balance wind tunnel test.Using the mode acceleration method to derive the along-wind direction,cross-wind direction and torsional wind-induced internal force response of the transmission tower.On this basis,the equivalent static wind load calculation method of the along-wind and the cross-wind direction of the transmission tower based on the internal force response is established.Through practical examples,the distribution of equivalent static wind load of the transmission tower along the tower 's height is obtained based on the internal force equivalent.4.Considering the coupling of the lattice and tower-line,the equivalent static wind load analysis method based on the internal force of the transmission tower under the combined action of the dynamic tension and the wind load is established.Through practical examples,the equivalent static wind load of the along-wind and cross-wind direction of the simplified model force is obtained.At last,the equivalent static wind loads of single tower and tower-line system are compared.