Abstract: This paper studies the finite element (FE) modeling oriented to structural health monitoring (SHM) of long cable-stayed bridge and the optimal sensor configuration based on the structural dynamic response. Firstly, the FE oriented SHM of Runyang Cable-Stayed Bridge (RYCB) is developed using ANSYS. Model analysis of RYCB is carried out using the developed FE model. Taking the non-diagonal elements of the MAC matrix as target function, and increasing or decreasing the number of degree of freedom (DOF), the optimal sensor placement of the bridge is obtained by minimizing the target function. Validation of the sensor placement is checked with the results obtained from the ambient vibration test of RYCB. It is shown that the sensor placement obtained from the measured data of RYCB is coincident with the result calculated from the FE model. The sensor placement obtained from the FE model of RYCB is valid from the experimental point of view.

Key words: long-span bridge, finite-element model, dynamic characteristic, sensor placement, model assurance criterion (MAC)