Bridge-Deflection Estimation through Inclinometer Data Considering Structural Damages

A new framework for bridge-deflection estimation through inclinometer data is presented in this paper. Whether the structure is damaged or not, deflection could be precisely estimated via the finite-element model (FEM) combined with the partial least-square regression (PLSR) method. In addition, damage localization is achieved at the same time. First, the deflection of a damaged structure is equivalent to that of an undamaged structure but subjected to special virtual loads. Second, the basis functions used in regression are calculated by the FEM of the undamaged structure rather than pure mathematical derivations. Third, the PLSR model is built on the basis of these basis functions and measured inclination data. By solving the PLSR equation, all the nodal inclinations and corresponding nodal loads of the structure could be obtained despite a limited number of measured nodes. Finally, the rotation-displacement transfer matrix is derived to reconstruct deflection from estimated inclinations, and the changes in nodal loads are served as damage indicators. To verify its effectiveness, numerical simulations considering various damage scenarios and different noise levels are performed. The results indicate that the proposed method is quite accurate and reliable in deflection estimation, and it could provide rough damage localization as well, which reveals a great potential in the field of structural health monitoring. (C) 2016 American Society of Civil Engineers.