A Linear Time-Domain Method for Structural Dynamics Identification

Abstract

A two-stage, time-domain structural dynamics identification method, that circumvents some of the main drawbacks of current techniques, and combines good noise rejection properties with a low computational load and accurate modal parameter extraction, is proposed. In the first stage of the method a discrete model is obtained through a linear estimation scheme and a systematic and effective modeling strategy. In the second stage the modal parameters are evaluated according to a new procedure that is capable of detecting and correcting large errors that may be introduced into the modal parameter estimates through the discrete-to-continuous transformation. The proposed method yields consistent modal parameter estimates at a low computational load, and is well-suited for microcomputer implementation. Its effectiveness is finally demonstrated with both simulated and actual experimental data.