High Resolution Mode Shapes Identification of Bridge Using Limited Sensors

In this paper, a new method is proposed for high resolution mode shapes identification of bridge using a limited number of sensors based on proper orthogonal decomposition (POD). Through the physical interpretation of the POD for a simple bridge under moving load, the components of generalize coordinate of POD are verified as the instantaneous status of the modals of the bridge. Based on the physical interpretation, the results proved that each component of the POD consists of a mode shape and the dynamic information of this mode, so that the mode shape can be identified by filtering the dynamic information. This mode shape with a high resolution is completely different from the traditional method which can only provide a spare mode shape because of the limitation of sensors. The simulation results proved that the proposed method can accurately identify the mode shapes with a high resolution.