Cointegration technique to account for environmental variability in a concrete dam

• Type: Article in International Conference Proceedings Book
• Date: 2024

Authors

Cunha, A. (Author) FEUP; Pirrò, M. (Author) Other; Gentile, C. (Author) Other; Magalhães, F. (Author) FEUP; Sérgio Pereira (Author) FEUP

Conference proceedings International

Title: Procedia Structural Integrity

Pages: 669-676

5th International Conference on Structural Integrity, ICSI 2023

Funchal, 29 August 2023 through 1 September 2023

Indexing

Scopus - 0 Citations

Other information

Authenticus ID: P-018-3FF

DOI: 10.1016/j.prostr.2024.09.325

Abstract (EN): Within Operational Modal Analysis (OMA) and Structural Health Monitoring (SHM) frameworks, novelty analysis aims to detect structural anomalies by inspecting the time evolution of the modal parameters of a structure subjected to ambient (unknown) excitations. However, real structures are subjected not only to structural anomalies, but also to environmental and operational variability (EOV), so it is necessary to remove EOV effects from damage-sensitive features. The paper presents an application of Cointegration technique to account for EOV on natural frequencies: given a set of non-stationary time-series, Cointegration builds a stationary linear combination of them, the cointegration residual, which is purged from the common trends mainly associated with EOV. The coefficients of the linear combination are determined by a maximum-likelihood multivariate technique, employing the natural frequencies within a training period, in which the structure is supposed to be in healthy conditions, under normal EOV. Once trained, the computed coefficients are used to test natural frequencies from unknown scenarios. The obtained cointegration residual will maintain its stationarity, as long as the structure behaves in normal conditions. Compared to traditional techniques, the Cointegration relies on more general operations, such as the construction of a linear combination given a set of modal parameters. The application of the presented procedure is exemplified with data measured in Baixo Sabor dam (Portugal) during the first two years of monitoring, which include the first filling of the reservoir. © 2024 Elsevier B.V.. All rights reserved.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7