Movable anchorage systems for vibration control of stay-cables in bridges

• Internal damping systems in cable-stayed bridges.
• Movable anchorage systems.
• Vibration control of cables.
• Exact eigenfrequencies and eigenshapes of stay-cables.
• Effective spring–damper combinations.

Cables are efficient structural elements that are used in cable-stayed bridges, suspension bridges and other cable structures. These cables are subjected to environmental excitations such as rain and wind induced vibrations. Rain–wind induced stay-cable vibrations may occur at different cable eigenfrequencies. Therefore, external transverse dampers have to be designed for several targeted cable modes in order to decrease the oscillations amplitude and to finally diminish them. For the analytical study of such problems, one may usually employ finite series or sinusoidal forms. In this paper, the real eigenfrequencies and shape functions are determined and used. This paper aims to study the optimum state and characteristics of such a damper as well as its influence on the cable’s vibrations using the real cable modes.