Abstract:
During the last decade, many vibration-based structural health monitoring systems have been successfully implemented
in different structures such as bridges, towers, stadia and wind turbines, with the aim of studying the
structure dynamics and its evolution over time, eventually detecting the occurrence of novel structural behaviour
that may indicate the presence of damage.
Such vibration-based monitoring systems generally rely on the identification of modal properties, which are
then used as monitoring features. Therefore, from operational modal analysis to the tracking of those features
and finally to data normalization, many processing steps occur that depend on the accuracy of the identified
modal properties. Thus, the estimation of the uncertainties associated with the identified modal properties increases
the robustness of this process.
In this context, data obtained from the continuous dynamic monitoring of a concrete arch dam has been used
to evaluate the gains of quantifying the uncertainties of modal properties, evaluating in particular the effect of
taking these uncertainties into consideration when performing automated operational modal analysis, modal
tracking and data normalization. Nevertheless, it is observed that the most significant gains of considering
estimates uncertainties occur when these quantities are used for removing outliers during modal tracking.