Inertial mass damper for vibration control of cable with sag

Zhi-Hao Wang,Bu-Qiao Fan,Zheng-Qing Chen,Hui Gao

doi:10.1177/1461348418814967

Abstract

It has been theoretically predicted that superior supplemental damping can be generated for a taut cable with an inertial mass damper. This paper extends previous studies to investigate the effect of the cable sag on the efficiency of an inertial mass damper. The general dynamic characteristics of an inclined sag cable with an inertial mass damper installed close to the cable end are theoretically investigated. The parametric analysis of the inertial mass and the damping coefficient of the inertial mass damper are conducted to evaluate the control performance of the cable with different sags. The results show that the inertial mass damper can alleviate the negative effect induced by the cable sag, and the cable sag can even increase modal damping ratios provided by the inertial mass damper. Sags of stay cables used in actual bridges only affect nearly symmetric vibrations of cables, while having little impact on nearly antisymmetric vibrations. The effect of cable sags will reduce the optimal damping coefficient and inertial mass of the inertial mass damper for the first symmetric mode of the cable.

Highlights

Cables, such as those used in cable-stayed bridges, are often susceptible to excessive vibrations due to their high flexibility and low inherent damping characteristics.[1]
The supplemental damping induced by passive viscous dampers may be insufficient to eliminate vibrations effects of long-stay cables since the damper location is typically restricted to be close to the bridge deck for aesthetic and practical reasons.[3,4,5,6]
This study investigates dynamic characteristics of an inclined sag cable with an inertial mass dampers (IMDs) installed close to the cable end

Summary

Introduction

Cables, such as those used in cable-stayed bridges, are often susceptible to excessive vibrations due to their high flexibility and low inherent damping characteristics.[1]. For the IMD with large inertial mass (me;1!1:0), the first modal damping ratio of the cable with the IMD decreases faster than that of the passive viscous damper with the increase of cable sag.

Results

Conclusion