Abstract
Cable-girder coupled vibration of cable-stayed bridge is analyzed by finite element method. Sutong Bridge is used as an example. Cable is simulated with one element cable system (OECS) and multiple element cable system (MECS). OECS model and MECS model are built for Sutong Bridge respectively. Global modes of the bridge are gained with OECS model. Local modes of cables and coupled modes of cable-girder are obtained by MECS model additionally. Therefore, the coupled vibration phenomenon is presented. Analysis results show that the coupled vibration will occur when the frequency ratio of local cable frequency to global bridge frequency is close to 1:1 and the cable vibration amplitude will be much larger. Therefore, the cable-girder frequency ratio should not design to be 1:1 to avoid the cable-girder coupled vibration in the design of a cable-stayed bridge.