Influence of cable dampers on cable-stayed bridges

Cable-stayed bridges have seen a wider application in recent years, with many having longer and longer spans. Modern cable-stayed bridges use numerous cables to support the stiffening girders. Many cable dampers are installed to mitigate cable vibration. This paper focuses on the effect of a cable damper on the dynamic characteristics of the whole cable-stayed bridge, especially modal damping. A practical model comprising the cable, girder and damper is developed to analyse the relationship between system modal damping and the performance of a cable damper with the complex mode method. A test model with cable, girder and damper was made to verify the theoretical results. A finite-element model of a simplified cable-stayed bridge based on a test model is adopted to assess the effects of cable dampers on the anti-seismic performance and wind-resistant behaviour of the cable-stayed bridge. The results show that the cable dampers of a cable-stayed bridge can increase the modal damping of the whole bridge.