SI 기법에 의한 단자유도 구조물의 지진동 시간단계별 손상 평가

초록

A nonlinear time-domain system identification (SI) algorithm is developed to assess structural damage due to earthquake vibration in real time. The method has been tested with a structure of a single-degree-of-freedom even though a SI algorithm for multi-degree-of-freedom structural systems is proposed in the paper. The algorithm is developed by using an equation error estimator based on the assumption of complete measurements in degrees of freedom of the analytical model. The error is defined by an incremental form of the dynamic governing equation. A constrained optimization tool in MATLAB is utilized to catch the variation of stiffness and damping in real time during earthquake motion. Damage due to earthquake motion is simulated by varying stiffness and damping parameters with time. The effects of time-window size, starting values for parameters, and measurement noise on the identification are investigated through simulation studies.