Vibration-Based Monitoring of Civil Structures with Subspace-Based Damage Detection

Abstract

Automatic vibration-based structural health monitoring has been recognized as a useful alternative or addition to visual inspections or local non-destructive testing performed manually. It is, in particular, suitable for mechanical and aeronautical structures as well as on civil structures, including cultural heritage sites. The main challenge is to provide a robust damage diagnosis from the recorded vibration measurements, for which statistical signal processing methods are required. In this chapter, a damage detection method is presented that compares vibration measurements from the current system to a reference state in a hypothesis test, where datarelated uncertainties are taken into account. The computation of the test statistic on new measurements is straightforward and does not require a separate modal identification. The performance of the method is firstly shown on a steel frame structure in a laboratory experiment. Secondly, the application on real measurements on S101 Bridge is shown during a progressive damage test, where damage was successfully detected for different damage scenarios.

Statistical subspace-based damage detection with estimated reference

“…The excitation direction is approximately 30 • rotated out of the in-plane-direction. Further details of the test setup can be found in [50].…”

The Example of using long-term monitoring and non-invasive measurements for Structural Health Monitoring. Cause study of St. Anna's Church in Warsaw

“…In order to determine the horizontal displacements of the Church, tower and retaining wall, reflective sights were set up on different levels and structures of the Church. The reference points (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24), control points (1-7) and total station positions (101, 102 and 103) are shown in Figure 5. This figure also includes a sketch of the observations made.…”

“…To monitor the gradual deterioration of antique buildings and their decorative parts such as frescoes, wall paintings, etc., different measurements techniques (classical surveying, photogrammetry, remote sensing, electromagnetic spectroscopy, etc.) [5] and comprehensive analysis (structural health monitoring analysis, operational modal analysis) [6][7][8][9][10][11] are commonly used. When proper methods of conservation, maintenance of cultural heritage objects, and establishing a schedule of conservation works, it is necessary to identify the factors affecting the degradation of the object.…”

Subspace‐based Mahalanobis damage detection robust to changes in excitation covariance

“…A solution to that problem lies in the design of a damage detection residual, whose mean value must be independent of such changes. This was for example achieved by a robust subspace residual relying on the singular value decomposition of the output covariance Hankel matrix, 35 whose robustness was confirmed on experimental data 40 . A drawback of this approach is the assumption that the reference model is perfect, whereas in most applications, it has to be estimated from data.…”