Dynamic Parameters Identification and Finite Element Model Updating for Continuous Rigid Frame Bridge

Abstract

A three dimensional FE model of a long-span prestressed continuous rigid frame bridge was constructed and the modal analysis was performed by using ANSYS. The real dynamic parameters of this bridge were identified by using the Frequency Domain Decomposition (FDD) method and the Eigensystem Realization Algorithm (ERA) method from the acceleration data recorded by the monitoring system on this bridge. A refined FE model of this bridge was obtained by updating the initial FE model using the identified modal parameters. The research result shows that (1) the modal parameters of this bridge can be identified with good accuracy from the acceleration responses collected by the monitoring system, and the identified modal parameters can be used to update the initial FE model; (2) the updated FE model can accurately reflect the structural dynamic characteristics of the bridge, and the updated physical parameters have good connectivity with the physical condition of the bridge.