Seismic damage assessment of a bridge pier by nonlinear time-domain system identification

초록

A nonlinear time-domain system identification (SI) method is developed and has been applied for a seismic damage assessment on a bridge pier. The method is to assess seismic damage using structural response measured during an earthquake motion without any additional vibration tests to obtain pre- and post-earthquake responses of the structure. The system identification algorithm is formulated based on an incremental form of the dynamic governing equation with the consideration on a nonlinear behavior of a structural system. A simulation study has been carried out with a single-degree-of-freedom (SDOF) model for a bridge pier and assumed an elasto-plastic response. Damage due to earthquake motion is simulated by varying stiffness and damping parameters with time. The effects of time-window size, initial values for parameters, and measurement noise on the identification are investigated.