Abstract
In this study, a field experiment on a truss bridge is conducted to investigate its modal change due to member's fracture. A diagonal member is cut in the experiment and a heavy vehicle passed the bridge to excite the bridge before and after introducing damage. High repeatability of responses of the bridge and vehicle in the spatial domain is observed. Variations of the mode shapes as well as singular value spectrum obtained by FDD due to damage are observed in comparing to those before applying damage. Observations also demonstrate that the kurtosis of the independent components of bridge responses could be an index to represent variation of bridge health condition. However, in vehicle responses, it is still a challenging task to detect clear feature of modal change caused by bridge damage.
