A control method for multi-mode vibration of a cable

Abstract

The invention provides a multi-mode vibration damper and a tuned mass damper (TMD) combination damping scheme and system parameter optimization design method for cable low-order wind and rain excitation and high-order vortex excitation. Dampers are arranged at two different positions on the cable, among which the damper controls the low-order wind and rain vibration, and TMD is aimed at the high-order vortex vibration. This method can solve the problem of high-order vortex vibration in the traditional single-point installation damper system on the cable. The parameter design includes the following steps: design the position and parameters of the damper according to the additional damping requirements of the modal vibration with the cable frequency below 3.0 Hz; The damper is close to the stagnation point of the vibration when the vibration is similar; the installation position and parameters of the TMD are determined according to the mode that the high-order vortex vibration is prone to occur. This method is beneficial to eliminate the hidden danger of high-order eddy vibration in the ordinary cable-damper system, and TMD has no influence on the optimal parameters and vibration reduction effect of the damper. The installation position of TMD is close to the cable end damper, which is convenient for installation, maintenance and replacement. It is suitable for vibration treatment of cables in new structures and cables in existing structures.

Description

technical field [0001] The invention belongs to the field of cable structures, and relates to the vibration control technology of the cable structure, in particular to the multi-mode vibration control technology of the cable of the cable-stayed bridge. Background technique [0002] Due to the characteristics of light weight, axial bearing capacity and high rigidity, stay cables have been widely used in the field of structural engineering, including cable-stayed bridges, suspension bridges, suspension rod arch bridges, and mast tower structures anchored by cables. Taking the typical cable-stayed bridge as an example, it has been widely constructed all over the world, especially in China, due to its aesthetic and economical advantages. As of 2019, a total of 55 cable-stayed bridges with a span of more than 500 meters have been built in the world, and my country has 36; a total of 47 cable-stayed bridges with a span of more than 500 meters are under construction, and my country...

AI Technical Summary

Problems solved by technology

The actual measurement results show that this method is not effective in controlling the high-order vortex vibration of the cables, and the method is difficult to install on bridges in the operation phase.

In addition, the method of installing a high-order vortex damper for controlling the cable at the end of the tower also has problems such as installation and maintenance difficulties; adding a damper at the end of the beam will affect the optimal parameters and vibration reduction effect of the original damper

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