Abstract
Japan is a seismic country and many structures were built in the highly economic growth period, then deterioration of structure becomes an important problem. So the structural health monitoring is strongly desired. Generally stiffness of the structure decreases when the structure is damaged by the load such as earthquakes. If this parameter can be estimated, the damage level of the structure can be evaluated. In this paper, real-time health monitoring strategy using multiple model method is proposed. Only the acceleration of the top floor is used for estimation. The estimator consists of two procedures. In the first step, the damaged story is detected. In the second step, the stiffness of damaged story is estimated. Simulation studies and experiment are conducted for four story frame structure, and the effectiveness of the proposed algorithm is examined.