Stay cable vibration control method

Abstract

The invention belongs to the field of structural vibration control, and in particular relates to a semiactive stay cable control method of a variable damper based on non-linear friction type damping. The method provided by the invention comprises the following steps that: according to displacement amplitude of a cable at a damper, a damping force is continuously regulated from high to low; and under the action of a corresponding damping force, displacement of the damper is always located in the previous period when the damper is locked, thus the obtained modal damping ratio is always high. A concrete semiactive control algorithm is that the modal damping ratio obtained in each period is equal to an attenuation curve of a stabilization system, wherein the attenuation curve is in exponential attenuation. The damping force provided by the invention is always dissipated, thus performance is stable and robustness is good. The system modal damping ratio obtained by the invention is higher and is much higher than a passive optimal modal damping ratio obtained by a linear viscous damper, thus a damping effect is good. The semiactive control method provided by the invention is simple and practical and is convenient to operate.

Description

technical field [0001] The invention belongs to the field of structural vibration control, and relates to a method for controlling a stay cable by a variable damper based on nonlinear friction damping. Background technique [0002] As the spans of cable-stayed bridges increase, the stay cables become longer and longer. As the main load-bearing component, the stay cable has large flexibility, light weight, low internal damping, and wide natural frequency distribution, and it is very easy to generate strong vibration under the action of environmental excitation (such as wind and rain excitation) or the displacement of the beam tower at the supporting end. This large-scale vibration will cause premature fatigue failure of the cable; cause damage to the connection between the cable and the tower beam; and make the public lose confidence in the safety of the bridge. [0003] The most commonly used measure for cable vibration reduction is to install dampers at the cable ends. In ...

AI Technical Summary

Problems solved by technology

Third, the passive viscous damper with a fixed installation position can add an optimal damping ratio to a certain vibration mode, but the additional damping ratio to other vibration modes cannot reach the optimal value, which will affect the multi-mode vibration of the cable The damping effect of

However, very few of its theoretical achievements have gone from research to application. Even if some have been applied in bridge construction, the control effect is not as good as passive optimal control, and it cannot reflect the advantages of intelligent control of variable dampers.

The root cause of the analysis is that there is a defect in the semi-active control method of the variable damper to the cable

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