Parametric vibration and control analysis of cable-tower-beam coupling system with viscous damper under random excitation

To evaluate the effectiveness of integrating linear viscous dampers with additional stiffness in reducing parametric vibration in cable stays, a vibration model of a cable-tower-beam system with viscous damper under random excitation is developed, and the equations governing the coupled motion are derived. The MilsteinPlaten method is recommended for directly obtaining the random vibration time history of the vibration model. The accuracy of the method is validated by comparing it with the finite element method, followed by an analysis of the vibration control factors of the stay cable. The results show that increasing the supplementary stiffness and the installation position ratio of the damper results in a more significant change in the vibration frequency of the cable. There is an optimal ratio of additional stiffness and installation position. Within the optimal range of values, increasing both variables result in a more effective reduction in cable amplitude. Once the optimal value is exceeded, the diminishing effect on reducing the amplitude becomes less noticeable. Increasing the spring stiffness on the rear side of the bridge tower can also reduce the cable's vibration response. The research results provide a theoretical basis for developing vibration reduction strategies in cable-stayed bridge cables.