Wind-induced Dynamic Response Analysis Of High Voltage Transmission Tower-line System

High voltage transmission line as a form of large-span and high flexibility structure, during its service time, wind load and seismic effect are significant。Wind load compared with seismic effect is more frequent, lead to wind-induced disasters are more than the disasters caused by the seismic effect.The current structure code of the tower-line system is separate transmission tower and transmission line before structure design. The code put transmission line’s wind load as a static load on the suspension point, so in the calculation it can’t consider the interaction vibration between transmission tower and transmission line. In recent years, several wind-induced damage accidents show that the original design specification has its limitations, from the angle of the coupling about the tower-line system has its practical significance in wind-induced vibration.This thesis first introduce the finite element modeling process of tower-line system, then introduce the wind speed time history simulation method and its implementation process.This thesis performed quasi-static analysis at0°,45°,60°,90°wind angles accordance to the transmission tower code. Obtained that the nodes of transmission tower’s main material are increasing with the increasing of wind angles at vertical line direction; on the contrary, the maximum displacement along the line direction is decreasing when the wind angles are increasing.This thesis have also done modal analysis on transmission tower, transmission lines and tower-line system, find that tower-line system’s vibration have a significant low-frequency, dense modal characteristics. After considering the tower-line coupling effect, the dynamic characteristics of the transmission tower will obvious changed, since the vibration characteristics of its low frequency will be excited.This thesis performed tower-line system’s time history analysis at0°,45°,60°,90°wind angles and tower-line system’s response under different wind speeds at90°wind angle. Got that insulators have a regulatory role to the vibration of the connect transmission lines, so that the dynamic tension of the two sides can be converge; the tower-line system’s coupling effect is enhance with the wind angle increasing; different from the quasi-static analysis, the nodes of transmission tower’s main material at time history analysis are increasing with the increasing of wind angles both at vertical line direction and along the line direction when the wind angles are increasing, the space twist is also increasing with the increasing of wind angles; the axial stress of tower body’s angle steel are obvious impacted by the conductor and insulator’s vertical excitation; the tower-line system’s coupling effect are increasing with the wind speed increasing, it is require to consider the impact of coupling effect under design wind speed; the transmission tower code of structure design about60°,90°wind angles are unsafe, it is. necessary to consider the effect of tower-line system’s coupling effect.