Time Domain Identification of Frames under Earthquake Loadings

The purpose of this paper is to examine the adaptive identification method and the nonlinear system identification technique through numerical simulation on seismic response of building structures. For the identification of a time-variant system and a system with an abrupt change of modal parameters, two parameter adaptation algorithms in recursive identification methods are discussed: recursive least square algorithm with constant trace and adaptive fading Kalman filter method. Based on the equivalent linear model, the time-variant model parameters can be identified. The tracking ability on the identification of a time-variant system is discussed. For the identification of the nonlinear system, the forward including algorithm and the neural network training algorithm were used to estimate the modal parameter of the nonlinear autoregressive moving average model, and the accuracy on the predicted output of nonlinear model identification was discussed.