Modal parameters identification using asynchronous data

Abstract

Operational Modal Analysis (OMA) allows one to identify the modal parameters (e.g., natural frequencies, damping ratios and mode shapes) of structure from its output-only response to ambient excitations. Modal parameters are often studied to provide information for Structural Health Monitoring (SHM): model updating, damage detection, damage localization and quantification. In vibration tests, multiple sensors are used to obtain detailed mode shape information and eigen-frequencies. Time synchronization among data channels is normally required in conventional modal identification approaches. If modal parameters can be identified precisely using asynchronous data, modal analysis tests can be more flexibly and economically conducted. In this paper, the effect of asynchronous data on operational modal analysis is investigated.