Finite element model updating of existing steel bridge based on structural health monitoring

Based on the physical meaning of sensitivity, a new finite element(FE) model updating method was proposed. In this method, a three-dimensional FE model of the Nanjing Yangtze River Bridge(NYRB) with ANSYS program was established and updated by modifying some design parameters. To further validate the updated FE model, the analytical stress-time histories responses of main members induced by a moving train were compared with the measured ones. The results show that the relative error of maximum stress is 2.49% and the minimum relative coefficient of analytical stress—time histories responses is 0.793. The updated model has a good agreement between the calculated data and the tested data, and provides a current baseline FE model for long-term health monitoring and condition assessment of the NYRB. At the same time, the model is validated by stress—time histories responses to be feasible and practical for railway steel bridge model updating.