Structural integrity monitoring for dependability

Abstract

Dependability of a structural system is a comprehensive concept that by definition describes the quality of the system as its ability to perform as expected in a way that can justifiably be trusted. One of the attributes of dependability is integrity, which can be interpreted as the absence of improper alterations of the structural configuration. The assessment of the integrity during the whole life-cycle can be carried out efficiently by implementing a monitoring system able to detect and diagnose any fault at its onset. The essential feature of the monitoring system dealt with in the paper is the elaboration of data gathered on site by a combination of simulation and heuristics. In detail, the first part of the paper deals with the extension of the concept of dependability, as formulated in computer science, to structural engineering. The second part illustrates a two-step hierarchical strategy for the assessment of the integrity of a structure through monitoring of its response under ambient vibrations; Bayesian neural network models are used for fault detection and diagnosis from observable symptoms. In the first step, the occurrence of any fault is detected and the relevant portion of the structure identified; in the second step the specific element affected by the fault is recognised and the intensity of the alteration of the structural performance evaluated. The strategy is applied to assess the integrity of a long-span suspension bridge subjected to wind action and traffic loading. As the bridge is under design, measured data are simulated by analysing the response of a detailed FE model of the whole structural system. The final objective of the study is the optimal design of the integrity monitoring system for the bridge. © 2011 Taylor & Francis

Genetic Algorithms for the Dependability Assurance in the Design of a Long‐Span Suspension Bridge

“…In the following paragraphs, the dependability attributes, means, and threats (Figure 3) are introduced and briefly discussed, extending what is reported in Arangio et al (2010).…”

“…In particular, in the field of electronic systems engineering, the concepts of dependability and dependable system have been defined and a framework has been set for the dependable design, creation, operation, and management (Laprie, 1992). This framework has been extended to complex structural systems, as integration to the broadly accepted structural requirements for the design, construction, and maintenance of structures, when considering the optimization of the design process of the system within a performance‐based approach (Arangio et al, 2010).…”

Bayesian Methods for Updating Dynamic Models

“…Hence, the most plausible model class is the one that possesses the best trade-off between the data fitting efficiency and robustness to modeling error. This approach has been applied to a number of engineering problems, including architecture of neural networks [105,147], damage detection [148], estimation of fault rupture extent [149]; identification for hysteretic structural dynamical models [150], air quality modeling [151], soil compressibility relationship [152], biomedical engineering [153], environmental effects to structural modal parameters [154], structural integrity monitoring [155], crack detection [156,157], and seismic attenuation relationship [158]. For more general cases in which the Gaussian approximation is inappropriate, one may use the transitional Markov chain Monte Carlo simulation method [159] to evaluate directly the evidence integral in Eq.…”

DInSAR for Road Infrastructure Monitoring: Case Study Highway Network of Rome Metropolitan (Italy)

“…The quantitative assessment of ground displacement affecting infrastructure is traditionally based on ground instrumentation, using automatic total stations, ground, and mobile laser scanners, with sub-centimeter precision that are useful for maintenance processes [1]. Space-borne Differential SAR Interferometry (DInSAR) is an alternative solution that can be fully assimilated into ground monitoring.…”