Identification of Linear Structures Using Discrete‐Time Filters

Most of the previous studies considered structural system identification in the continuous‐time domain. The discrete‐time approach to the problem is more natural since all the recordings are in the discrete‐time form. This study presents a discrete‐time method for system identification by using discrete‐time linear filters. The method itself is well known in electrical and systems engineering fields, and therefore is not new. The objective in the paper is to present the method by emphasising its relation to the more familiar continuous‐domain modal analysis approach that is widely used in structural engineering. In addition to the method, some practical but important problems are also discussed in the paper, such as the processing of data, the selection and validation of models in the identification, and the detection of soil‐structure interaction. As an example, a 12‐story building was identified by using recordings from the magnitude 6.4, San Fernando, California earthquake of February 9, 1971.