Output only estimation of inter-story drift angle for buildings using one accelerometer

In this paper, we propose a method for estimating inter-story drift angle using only one accelerometer without knowing input motion. The proposed method is based on two assumptions. One is that the response is represented by the superposition of the response of onlylowermodes. The other is that mode vectors and participation factors are available from the design model. Based on these assumptions, first, we estimate modal frequencies and damping ratios using the subspace method from obtained acceleration date. Second, we decompose observed acceleration data to each mode by band pass filtering. Third, we calculate mode response by solving the vibration equation of each mode. It was verified that this method could successfully estimate the modal response as well as the inter-story drift angles and the resuite were better than the existing method.