Response-based time-invariant methods for damage localization on a concrete bridge

This paper is integral part of the Special Issue on “Existing Concrete Structures: Structural Health Monitoring and Testing for condition assessment.” It deals with vibration-based methods (VBMs) for damage localization that approach the problem of structural integrity management through the analysis of the dynamic response of the structure under ambient or forced vibrations. In the last years, these methods received a widespread interest in the structural health monitoring (SHM) community due to the possibility to use them for continuous SHM and real time damage identification. The performance of these methods is commonly verified on numerical models or laboratory specimens that, by their nature, cannot reproduce all the sources of uncertainties found in practice. The availability of data recorded on a real benchmark, the S101 bridge in Austria, enabled the comparison of three well known vibration-based time-invariant methods for damage localization, namely, the curvature method, the interpolation error method, and the strain energy method. The bridge, built in the early 1960, is a typical example of a European highway bridge. Responses to ambient vibrations were recorded both in the undamaged and in several different damage scenarios artificially inflicted to the bridge. This paper reports the results of the application of the three mentioned methods of damage localization to this case study.