Study on Wind Vibration Coefficient Chang Rule of Cup Type Transmis- sion tower Considered Abrupt Change in Stiffness

Abstract: Wind load is the key and sensitive for tower structure but national standards tend to think that level stiffness change of cup type transmission tower is uniform along the height. The structure stiffness change of cup type transmission tower was simulated innovatively and found its nonuniformity. The result shows that the structural stiffness uniformly changes along the height when the flow direction parallel to the cross arm while the stiffness of crank arm and cross arm has mutations when the flow direction is vertical to the cross arm. Horizontal stiffness change causes a significant change of wind vibration coefficient. A simulation analysis was performed about wind-induced response of cup-tower to obtain the change rule of wind vibration coefficient. Furthermore, proposed the approximate calculation formula of wind vibration coefficient at crank arm and cross arm.