Damping of Stay-Cable Vibrations: Modeling Overview and Design Implications

Published

April 25, 2006

Author(s)

Joseph A. Main, Nicholas P. Jones

Abstract

Dampers have become widely accepted as an effective means of stay-cable vibration suppression and have been implemented on numerous bridges around the world. Dampers are typically attached to the stays transversely near the anchorages, and different types of damping devices have been used, including fluid dampers and friction dampers. The dynamic behavior of the resulting cable-damper system has been the subject of much investigation in recent years, with the aim of facilitating effective damper design. For the simple case of a taut string with a linear viscous damper near a support, a universal estimation curve has been identified, which relates the damping ratios in the first few modes to the nondimensional damper coefficient. This curve is of great utility in damper design, and it reveals the existence of an optimal damper tuning, for which the damping is maximized in a particular mode. For larger values of the damper coefficient, the damper begins to lock the cable locally, resulting in decreased efficiency. Recent modeling efforts by the authors have shown that the general form of this universal estimation curve can be extended to account for a number of complicating influences of importance in damper design. These influences include nonlinear damper behavior, bending stiffness of the stay cable, and transverse stiffening by rubber bushings attached near the anchorages. This presentation will give an overview of recent research on these topics, highlighting key results of importance in design. A one-page expanded abstract will be published in the workshop proceedings.

Proceedings Title

Workshop on Wind Induced Vibration of Cable Stayed Bridges| 2006

Conference Dates

April 25-26, 2006

Conference Title

FHWA

Pub Type

Conferences

Keywords

cable-stayed bridge, damping, stay cable, vibration

Citation

Main, J. and Jones, N. (2006), Damping of Stay-Cable Vibrations: Modeling Overview and Design Implications, Workshop on Wind Induced Vibration of Cable Stayed Bridges| 2006 (Accessed April 26, 2024)