Modal Parameter Estimation of Model Steel Bridge Using System Identification Methods

Civil engineering structures are exposed to different external effects which change their dynamic characteristics. The fact that damage can alter stiffness, and/or energy dissipation capacity of a structure which in turn results in detectable changes in its vibration signature is the underlying principle of vibration-based structural health monitoring (SHM). An important step of SHM process is the estimation of modal parameters. In this study, modal parameters of a steel bridge are estimated using ERA and NExT-ERA system identification techniques. A calibrated finite element model of the bridge is obtained using the estimated modal parameters. Accurate damage identification of a structure depends on accurate estimation of modal parameters. The calibrated model in the future can be used to assess the parameters affecting modal parameter estimation therefore accurate damage identification