Shake table test and numerical model update for a viscous damper isolated cable-stayed bridge

This study focused on the seismic responses and numerical model update of fluid viscous dampers (FVDs) isolated cable-stayed bridges excited by ground motions with different frequency contents. A 1/20 scaled three-span cable-stayed bridge was designed, constructed, and tested on a facility with four shake tables. Four ground motions with different frequency contents were adopted to excite the shake model. Then, a numerical model update framework of the shake table test was introduced, which combines the differential evolution (DE) algorithm and the parallel finite element computing technique. In addition, a time history response-based objective function was established that considered various responses of the bridge components. The shake table test results reveal that frequency contents affect the seismic responses of the cable-stayed bridge, and the ground motions with strong velocity pulses can amplify the displacements of the pylons and girder. In addition, the accelerations of the girder are relatively small and less sensitive to input ground motions. In general, the proposed method is efficient and accurate for updating the numerical model of the shake table test model.