Damage Detection and Localization for Continuous Static Monitoring of Structures using a Proper Orthogonal Decomposition of Signals

In the recent years, several structures have been equipped with permanent monitoring systems, able to record the response in terms of displacements and strains over very long periods of time and, theoretically, for the entire life of the structure. Despite of the number of applications, very few studies have been presented aimed at interpreting the data and at providing a means for detecting and localizing the insurgence of damage or material degradation from the measurements. The paper provides an approach to an algorithmic treatment of the data flows produced by continuous static monitoring systems. The proposed algorithm is the Proper Orthogonal Decomposition, a statistical method particularly suitable and versatile in multivariate analysis. However, its application in the field of damage detection for static monitoring is a new approach. The discussion will be based on data obtained by means of a computer simulation of a typical bridge structure subjected to environmental loadings. The POD will be used for studying a temporal and spatial correlation analysis between the structural responses measured at different sensor locations. The comparison in terms of damage indices of the responses from different sensors in time has shown to be able to detect damaged sections.