Enhancing vibration control in multi-cable hybrid network systems: A parametric study and optimization evaluation

For large-span cable-stayed bridges, cross-ties and dampers can work together for vibration mitigation of cables. Common analyses pay attention to the effectiveness of cross-ties and external dampers on two adjacent cables, fewer studies are available on the combined effect in multiple-cable networks. Investigating the optimization of multi-cable system parameters is a crucial problem for effective vibration mitigation. This paper proposes a model of the multi-cable hybrid network (MCHN) system. The corresponding characteristic equation is derived, and the analytical solutions for modal frequency and damping ratio are calculated. Furthermore, the results are verified through comparison with finite element and experimental results of a three-cable hybrid system. An analysis of the in-plane natural vibration characteristics of MCHN systems is presented, utilizing a numerical example of a three-cable MCHN system. Key parameters such as cable length differences, mass-tension ratio, cross-tie stiffness, damper number, damper location, and damping coefficient are considered to investigate their influence on the damping. A multi-modal optimization criterion (MANDR) based on maximizing the average of damping ratio is proposed by normalization of the system modes. When dampers are selected according to the optimization criterion of MANDR and installed in appropriate locations, the damping capacity can be better utilized.