Statistical system identification of structures using ARMA models

[摘要] The present study focuses on the estimation of the modal properties, i.e., natural modal frequencies, modal damping ratios, and mode shapes, of a structural system under ambient vibration based on the response data of the structure and the statistical properties of the stationary loading process. The corresponding input-output system is represented by a covariance-equivalent ARMA model which is univariate in the case of multiple input - single output and multivariate in the case of multiple input - multiple output. The mapping between the physical modal parameters and the ARMA parameters is established. Two different algorithms are used to estimate the covariance-equivalent ARMA models, namely the maximum-likelihood algorithm and a two-stage least-squares algorithm.An augmented system approach including both a fictitious ;;load;; system and a structural system is formulated to account for the non-whiteness of most realistic loading processes. Examples of its application are provided for the cases of earthquake, wave, and wind excitations.

[发布机构] Rice University

[效力级别] engineering