Vibration-Based Physical Parameter Identification of Bridge Structures under Traffic Excitation

A new compound method of physical parameters identification of bridge structures under traffic excitation is presented in this paper. Employing the dynamic nodal loading (DNL) approach, which could consider the dynamic response due to the road irregularities and vehicle inertia effect of a vehicle-structure system, the moving vehicle load could be converted into the transient load on each node in time domain. Then, the accelerate response of bridge structures calculated with the Newmark - ß method, is used to construct the displacement, velocity and acceleration response in the transform space. At last, the recurrence formula derived based on the principle of least squares, is utilized to obtain the physical parameters of bridge structures in the transform space. The feasibility and effectiveness of the proposed identification technique are demonstrated by a numerical example on the two-span Benchmark structure proposed by the bridge health monitoring (SHM) Community of International Association of Bridge Maintenance and Safety (IABMAS). With the proposed technique, information collected about the traffic such as the arrival time and speed of vehicles will directly contribute to improving the structural property identification. The method should be more accessible to theoretical significance and merit of potentially practical utilization.