Wind-induced Collapse Mechanism of Terminal Tower of Iced Transmission Line
The finite element dynamic analysis model is developed by using the collapsed terminal tower-line system as the object.Based on the harmonic superposition method and Davenport target spectrum,the time history curve of wind speed is simulated to determine the wind load on the iced tower-line.The investigation focuses on the wind-induced collapse mechanism and influencing factors of iced terminal tower-line system.Transient analysis is used to simulate the whole collapse process of the iced terminal tower-line system in order to reveal its wind-induced collapse mechanism.Under the action of eight grade wind load,the lower primary material of tower leg on the leeward side is the first to become unstable failure,which increases the stress of adjacent components.The iced terminal tower then suffers from instability or yielding failure of the local components in sequence,eventually causing the entire structure to collapse.The entire conductor tension in the terminal tower is non-equilibrium,which produces significant overturning stress in the tower leg.On the load proportion of equivalent stress of the failed elements,conductor tension accounts for more than 50％,and wind loads acting on the tower for more than 30％.The analysis of parametric influences leads to the conclusion that the wind direction angle of 90 degrees is one of the most dangerous wind load circumstances,while the most reasonable line direction is along the two orthogonal maximum inertia spindles of the cross section of terminal tower base.
万方数据
维普
