Structural model updating of steel box girder bridge using modal flexibility based deflections

The finite element models need to be updated to simulate the actual behavior of the structures. A simplified approach has been presented in this paper for model updating of steel box girder bridge using the virtual static deflections. The approach is based on the conversion of dynamic model to static model. The deflections used for the model updating are estimated from the modal flexibility matrix which requires only a small number of lower modes for accurate estimation. An optimization process is adopted for the model updating. Dynamic tests have been performed on a two span continuous bridge for the verification of the proposed approach. It has been found that the updated numerical deflections obtained by the proposed method reasonably agree with the estimated deflections.