Nonlinear Analysis And Control Of Wind-Induced Vibration Of Single-Pole-Tower

The single-pole-tower has been widely used in the area of communication and electric power industy for a long time outseas. Recently, it has been promptly put into use in our country. Single-pole-tower has the prominent virtues of simple conformation, ease of construction, good appearance and less bulk, so it will have a bright future. In order to utilize this tower to the best, make its technology of design and manufacture more proficient, the author studies its static nonlinear analysis and control of wind-induced vibration.Wind load is the most important one of the single-pole-tower. The structure's lateral-displacement is large under the wind load calculated according to the Code, and the lateral-displacement is always crutial to the design of the single-pole-tower. But the method of calculating the lateral-displacement is not clear at the present. Based on the application of the single-pole-tower in communication tower, the author does a series of examples with different factors, such as height, diameter, thickness etc, Using linear elastic and the second-order elastic analysis method separately, and the original bending defect of the whole structure is considered when using the the second-order elastic analysis method. The result indicates that it is necessary to control the wind-induced vibration in order to reduce the lateral-displacement and it is advised to use the second-order elastic analysis method when designing the single-pole-tower with its height more than 50m.In order to get a deeper understanding of the nonlinear properties of the single-pole-tower and the influence degrees of its defects, the author carries out the complete-course analysis of the tower and gets the load-displacemnt curves, introducting the geometry defects and material defects. It can be concluded from the result that the influence of the defect is small on the structure's ultimate bearing load, however it is large on the structure's displacement, mostly coursed by the geomertry defects. It is advised to consier the geomertry defects besides using of the second-order elastic analysis method to design the single-pole-tower with its height more than 50m.It is necessary to control the wind-induced vibration of the single-pole-tower, but the ideal absorber compatible with the single-pole-tower is scarce. Considering small space in the single-pole-tower and its cheapness, the author tries to use the ball vibration absorber to control the wind-induce vibration of the single-pole-tower. Firstly, the author simulates the wind load time history of a real single pole communication tower by the computer. Secondly the principle of the ball vibration absorber is expatiated. Thirdly, the paper uses the time history method to analyze the tower with the absorber or not separately. Comparing the two model's analysis results, it could be found that the ball vibration absorber can control the structure's wind-induced vibration well. Based on the time history...