| In recent years,due to strong wind the transmission towers often collapse,and the destruction of the transmission tower-line system has brought great impact and loss to people's lives and the national economy.In view of the above problems,this paper research on dynamic respone analysis of transmission tower-line system and wind-induced vibrantion control in the multiple conditions,and proposes relevant vibration reduction measures to provide reference for practical projects.The main contents are as follows:(1)Based on the actual project of "typical design of 110kV transmission tower",this paper chooses suitable elements based on the principle of finite element to study the characteristics of transmission tower,insulator and conductor,uses small modulus of elasticity deformation to find the type of conductor(ground)line,establishes an accurate tower-line system model,and analyses the displacement,axial force,bending moment and stress of transmission tower under multi-working conditions,and with the industry.The results show that the wind load is the main load to control the displacement of the tower body,the pressure is the main control force of the tower body,the axial force at the legs of the tower is larger,and the contribution of the bending moment stress on the cross-arm is relatively large.The greater the bending moment value near the leg of the tower body,the more obvious the effect of the second-order bending moment stress is.(2)The dynamic response of transmission tower and tower-line system is studied,the coupling effect of wire addition on transmission tower is analyzed,and the vibration frequency and the change of array are determined.The influence of wind load on the structure is studied.The fluctuating wind is simulated by Kaimal wind speed spectrum along height,and the response law of transmission tower and tower-line system under different wind speeds is studied.The harmonic superposition method is selected for 15.M/s,20m/s,30m/s wind speed time history simulation.The simulation pulsating wind speed power spectrum is compared with the target power spectrum at 10m height,which proves the reliability of the simulation wind speed on the tower and creates conditions for the follow-up wind dynamic response.(3)The dynamic characteristics of transmission tower and tower-line system under different wind speeds are studied.The wind-induced response time history calculation of single tower and tower-line system is carried out by using the Newmark-? method.The responses of different wind speeds,different directions(X,Y)displacements,velocities,accelerations,axial forces and bending moments are analyzed.The results show that the response values of tower-line system gradually increase with the increase of wind speed.Compared with single tower,the addition of conductors makes the coupling of the system stronger,each response value larger and the structure system more stable.The control method of wind-induced vibration response of tower-line system is studied,and the influence of different dampers on transmission tower-line system is analyzed.The improved spring damper is used for vibration control.The dynamic characteristics of tower-line system with dampers are analyzed,and the coupling effect of conductors in tower-line system is analyzed.The nodes and special parts(tower legs and crossbars)are obtained at different wind speeds and without dampers.The displacement,velocity,acceleration,axial force and bending moment responses under the same direction(X,Y)are compared and analyzed.The results show that under the optimal wind speed control,the maximum displacement and acceleration at the top of the tower are reduced by 43.73%,36.20%,32.17%,27.92%and 11.14%respectively by the damper.The axial force and bending moment of the tower leg are reduced by 20.56%and 19.66%,and the structure system is stable. |
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