explaining operational modal analysis with data from an arch bridge

this tutorial paper aims to introduce the topic of operational modal analysis to non-specialists on the subject. first of all, it is stressed the relevance of this experimental technique particularly in the assessment of important civil infrastructure. then, after a synthesis of required theoretical background, three of the most powerful algorithms for output-only modal identification are presented. the several steps of these identification procedures are illustrated with the processing of data collected on a concrete arch bridge with a span of 280 m. as the use of operational modal analysis in the context of structural health monitoring is a subject under active research, this theme is also introduced and briefly exemplified with data continuously recorded at the same bridge.