研究期間：10108~10207;The purpose of this proposal is to investigate the feasibility of detecting structural damage location using the HHT method. The damage of initial stiffness reduction and nonlinear response to columns are disscussed respectively. The major working items are as follow: 1. The stiffness reduction of column section is used to simulate the initial damage of a structure. 2. The damage detection index, RB, evaluted from HHT spectrum, is used to detect the location of initial damage to a structure. 3. The wen’s model is adopted to simulat the nonlinear behavior of a column. Then the damage locaion of a structure is detected by using the damage detection index, RB. 4. The effectiveness of detecting the damage location in a real structure using the damage detection index, RB is demonstrated from the steel benchmark building data (NCREE-06-020).