Seismic structural health monitoring using the modal assurance distribution

• Published in: Earthquake engineering & structural dynamics Vol. 50; no. 9; pp. 2379 - 2397
• Main Authors: Quqa, Said, Landi, Luca, Diotallevi, Pier Paolo
• Format: Journal Article
• Language: English
• Published: Bognor Regis Wiley Subscription Services, Inc 01.07.2021
• Subjects: Assurance; clustering; Damage assessment; damage identification; Distribution; Earthquake damage; Earthquakes; Ground motion; Information processing; Mathematical models; nonlinear normal mode; nonlinear structure; Numerical models; Parameter identification; Reinforced concrete; Seismic activity; Seismic response; Signal processing; Structural behavior; Structural health monitoring; time‐frequency representation; time‐varying feature
• ISSN: 0098-8847; 1096-9845
• DOI: 10.1002/eqe.3451

Thanks to emerging techniques in the field of signal processing and due to improvements in smart sensing systems which enable the event‐triggered acquisition of high‐fidelity data at the occurrence of strong ground motion events, seismic structural health monitoring has grown considerably in the last few decades. In this paper, the modal assurance distribution, an alternative time‐frequency representation of the modal features of multivariate and multicomponent signals, is extended for application to short‐term nonstationary vibrational structural responses in which the system may manifest its nonlinear behavior. A general procedure for the extraction of the decoupled normal modes is presented, which allows the identification of instantaneous modal parameters in order to investigate in detail the structural behavior during earthquakes. Valuable information that cannot be recovered by means of traditional criteria can thus be exploited for accurate damage assessment. The results obtained for two case studies consisting of a numerical model with softening nonlinear behavior and a full‐scale experimental reinforced concrete benchmark show the potential and applicability of the method proposed for the integrity assessment of civil structures.