It is common practice in Structural Health Monitoring (SHM) to perform damage detection by detecting changes in subspace-based damage indicators. They are computed by comparing a reference state with the current (possibly damaged) state through a matrix based on the computation of residuals originated from the orthogonality defect of projected subspaces. In the last decades, several scalar indicators have been proposed based on the residual matrix. Still, a multivariate sensitivity analysis was not carried out to estimate the sensitivity of each indicator to the excitation changes. In this thesis, a covariance-based sensitivity analysis applied to a spatial truss structure is carried out to evaluate the sensitivity of eight damage indicators to ambient excitation covariance, damage severity, and damage location. The analysis aims at identifying the ranges of applicability of damage indicators within a simple statistical framework, possibly extendable to more general applications. It is argued whether any equivalent class of indicators can be obtained from the manipulation of the residual matrix. The role of damage location in the probabilistic assessment of damage is discussed: a methodological Bayesian approach, based on the results of the sensitivity analysis, is proposed for the development of a structural reliability analysis driven by damage indicators. An real-case application of damage detection tests is further presented for the Santa Maria di Collemaggio basilica.

Indicatori di danno subspace-based: dai test di rilevamento danni all'analisi di affidabilità strutturale / DI BATTISTA, Luca. - (2021 Apr 28).

Indicatori di danno subspace-based: dai test di rilevamento danni all'analisi di affidabilità strutturale

DI BATTISTA, LUCA
2021-04-28T00:00:00+02:00

Abstract

It is common practice in Structural Health Monitoring (SHM) to perform damage detection by detecting changes in subspace-based damage indicators. They are computed by comparing a reference state with the current (possibly damaged) state through a matrix based on the computation of residuals originated from the orthogonality defect of projected subspaces. In the last decades, several scalar indicators have been proposed based on the residual matrix. Still, a multivariate sensitivity analysis was not carried out to estimate the sensitivity of each indicator to the excitation changes. In this thesis, a covariance-based sensitivity analysis applied to a spatial truss structure is carried out to evaluate the sensitivity of eight damage indicators to ambient excitation covariance, damage severity, and damage location. The analysis aims at identifying the ranges of applicability of damage indicators within a simple statistical framework, possibly extendable to more general applications. It is argued whether any equivalent class of indicators can be obtained from the manipulation of the residual matrix. The role of damage location in the probabilistic assessment of damage is discussed: a methodological Bayesian approach, based on the results of the sensitivity analysis, is proposed for the development of a structural reliability analysis driven by damage indicators. An real-case application of damage detection tests is further presented for the Santa Maria di Collemaggio basilica.
Indicatori di danno subspace-based: dai test di rilevamento danni all'analisi di affidabilità strutturale / DI BATTISTA, Luca. - (2021 Apr 28).
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Descrizione: Subspace-based damage indicators: from fault detection tests to structural reliability analysis
Tipologia: Tesi di dottorato
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11697/170119
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