This work introduces a recent application of the online nondestructive damage assessment system into a cable-stayed bridge. A set\nof ambient modal parameters are automatically extracted every 20 minutes using real-time signal data collected from a total of 26\naccelerometers attached on the deck plate of the bridge. Then, a set of modal flexibilities are reconstructed by the combination of\nthe extracted modal parameters with the approximated modal mass of the girder. Next, the curvature of the modal flexibility is\napproximated by a central difference formula. Finally, the set of flexural damage index equations is constructed by comparing the\nmodal curvature of the damaged state to that of the undamaged state. Solving the overdetermined flexural damage index\nequations, the desired damage index is finally quantified. The resulting index clearly indicates the location and severity of the\npotential structural damage on the girder. Based on the overall performance of the implemented health monitoring system, the\nbridge operatorâ??s damage index control criteria are set to .............................
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