Bayesian operational modal analysis: Theory, computation, practice

Ambient vibration tests have attracted increasing attention over the last few decades because they can be performed economically with the structure under working condition without artificial loading. Ambient modal identification techniques do not require knowledge of the loading but they assume that it is statistically random. A Bayesian approach provides a fundamental means for extracting the information in the data to yield information about the modal parameters consistent with modeling assumptions. Issues do exist in the implementation and interpretation of results. This paper presents an overview of a Bayesian frequency-domain approach for ambient modal identification. Issues of theoretical, computational and practical nature are discussed, drawing experience from field applications.