Tuned mass-high damping rubber damper on a taut cable

Abstract

Due to their low intrinsic damping, stay cables in cable-stayed bridges are vulnerable to dynamic excitation. The cables have often been exhibiting undesirable and excessive vibrations, which result in increasing maintenance frequency and disruption to normal operations of the entire bridges. Mitigation of undesired cable vibration can be achieved by attaching a traditionally mechanical damper near the anchorage. Although utilizing this type of damper demonstrates vibrating diminishment in cables, the approach is not the most effective method due to geometric constraints. Tuned Mass Damper (TMD) has been used to overcome the deficiency of the traditional mechanical damper since it can be mounted anywhere along a cable. This paper proposes a new type of damper called the Tuned Mass - High Damping Rubber (TM-HDR) damper for increasing damping ratio of the cable. Oscillation parameters of cable with an attached TM-HDR damper are investigated in detail using an analytical formulation of the complex eigenvalue problem. As a result, optimal parameters of the damper can be evaluated and selected in order to reduce vibrations of cable. In addition, this paper demonstrates the effects of TM-HDR damper by using an example.