A study on physical models representing vibration responses of hanger cables in the Great Belt Bridge

Abstract

Monitoring bridges has been an important tool for many years to understand the condition of a bridge, and it is important because it can prevent damage and reduce the risk of human losses. In this study, the focus is to develop and investigate three different physical models representing vibration responses of the hanger cables in the Great Belt Bridge in normal operational conditions, because these components are subject to high vibration and loads. An approach for a model updating strategy is developed, and a comparative analysis of the three models is made to select the best-suited physical models for developing a Structural Health Monitoring strategy for the hanger cables. An iterative non-linear optimization method with the natural frequencies as the characteristic quantities is used for the model updating of one model, while for the two other models, model updating is conducted by solving for the axial load directly. The comparative analysis is conducted based on a plot illustrating the trend of the three models. It is concluded that the trend of the physical models is approximately the same, making it possible to switch from one model to the other with a deterministic correction. The updated results show good agreement between the physical and the actual model, and the simplest model, in relation to computational effort, can be chosen as the best-suited physical model and it is concluded that it is a pinned-pinned beam model.