Model Parameter Analysis And Damage Detection Of Rigid-Frame Continuous Beam Bridge Under Ambient Excitation

A model parameter analysis method under ambient excitation and a structural damage detection method for the rigid-frame continuous beam bridge are studied in this paper. The method combining the Next and ERA is researched to identify the structural model parameters, and the traditional mode curvature defference method for the structural damage detection is improved and validated by the model of Shandong Dongying Yellow River Highway Bridge. Then the temperature effect on the structural model frequency is analysed, and the model parameter identification results are modified. The main research contents are as followed:First, the method combining the Next and ERA is used to identify the structural model parameters of a rigid-frame continuous beam bridge. Based on the model of Shandong Dongying Yellow River Highway Bridge, the method is validated by simulation in many different conditions, such as different styles of ambient excitations, different noise levels and different parameter settings. Some suggestions are given to improve the identification result and remove the wrong model parameters.Second, the noise sensitivity of the mode curvature difference method is researched. Based on the different effects on the mode curvature difference between the structural damage information and the noise, the traditional mode curvature defference method is improved, and a new structural damage detection way which takes the product of the mode curvature difference as the damage index is proposed. The method is validated by the structural damage detection of Shandong Dongying Yellow River Highway Bridge.Finally, based on the structural vibration response data of the Shandong Dongying Yellow River Highway Bridge, the temperature sensitivity of the structural model frequency is researched. A linear relative model between the temperature and the model frequency is found to modify the model frequency identified online.