Two-Step Kriging-Based Finite Element Model Updating for a Scaled Cable-Stayed Bridge under Shake Table Tests

Abstract

Cable-stayed bridges exhibit pronounced nonlinear response under a large earthquake. To accurately capture their seismic behavior, a two-step finite element (FE) model updating procedure is proposed to refine FE models employing a Kriging surrogate model, implemented through the uniform design approach. In the first step, the focus is on updating the geometrical and material parameters whereas in the second step, different friction models of sliding bearings and damping parameters are refined while keeping the optimized geometrical and material parameters constant. Comprehensive sensitivity analyses and the nonlinear FE model updating are performed on a 1/20 scaled cable-stayed bridge for shake table tests. It is revealed that L1 norm percentage error is the optimal objective function to quantify the difference between experimental and numerical time history results. The two-step FE model updating procedure employing the Kriging surrogate model provides an effective technique for finding the optimal structural parameters, and the updated FE model is able to predict the actual seismic response of the scaled bridge with more accuracy. Moreover, the bearing friction behavior plays a significant role in the seismic response of the scaled bridges, emphasizing the importance of concurrently incorporating the effect of velocity and pressure on the friction behavior of sliding bearings during the FE modeling of cable-stayed bridges under seismic actions.