Cable bridge modal parameter statistical analysis under the time varying environment coupled with damage

Statistical analysis for modal frequencies and damping ratios of a cable-stayed bridge is performed accounting for the coupled effects of time varying environment and damage. Firstly, ERA combined NExT method is utilized to identify structural frequency and damping ratio. Than, BP neural network is employed to establish the relationship between temperature and structural modal parameters using long-term monitoring data. And then, the probability model of variation in structural modal parameter by temperature and noise is obtained. Finally, structure damage is identified by comparing the intersection probability ratio of modal parameter. The proposed approach in this study is verified.