1,721,066 research outputs found
Value of Information Analysis Accounting for Sensor Data Quality: focus on drift
Full text linkStructural health monitoring plays a crucial role in assessing the condition of civil structures, providing information for regular maintenance and post-disaster emergency management. However, the reliability of structural health monitoring outcomes can be compromised by sensor malfunctions. Over the past two decades, sensor validation tools have been proposed to identify and discard abnormal measurements before extracting information from the structural health monitoring system. The long-term benefits of structural health monitoring systems are commonly evaluated without considering the possibility of faulty sensors. This can lead to suboptimal maintenance decisions. Recently, a Bayesian decision theory-based framework has been introduced to account for different data quality issues and quantify the benefit of implementing a sensor validation tool. This novel approach expands the traditional Value of Information concept to encompass multiple "functioning" states of the structural health monitoring system. This paper mainly focused on a specific data quality issue, i.e., bias or drift in the monitoring outcome. Previous applications of this framework regard simplified decision scenarios, where the monitoring system was either “damaged” or “undamaged”, considering a fixed drift value. In this paper, the impact of uncertain drift levels on the Value of Information in structural health monitoring is investigated, addressing real-world complexities. A numerical case study is considered to illustrate the practical implications of the VoI framework
Synthetic Aperture Radar Interferometry for Structural Health Monitoring of Bridges: Potentialities and Open Research Questions
Full text linkThe development of synthetic aperture radar (SAR) interferometry has provided unprecedented opportunities to remotely analyze the behavior of civil structures, transcending traditional limitations associated with in-situ methods. However, while the effectiveness of SAR technology in monitoring wide-area geohazards is demonstrated in several applications, its extension to civil structures, which have a much smaller footprint, requires further investigation of several aspects. This paper investigates the potentialities and challenges connected with the use of SAR technology for civil engineering artifacts, fostered by the availability of remote satellite open data. Recently, the European Space Agency has introduced the European Ground Motion Service (EGMS) under the Copernicus program. This innovative and freely accessible resource provides comprehensive information regarding ground motion across Europe through multitemporal interferometric analysis of Sentinel-1 images acquired since 2015. In this paper the focus is on the Palatino Bridge in Rome, Italy. Data from the ascending and descending orbit are combined to obtain vertical and longitudinal displacements of the structure, allowing for a better estimation of the bridge's response to varying environmental conditions. Results are then compared with those obtained processing high resolution data from COSMO-SkyMed of the Italian Space Agency, showing the consistency of findings
On the standardization of procedures for Structural Health Monitoring
Full text linkThe aim of this paper is to outline the different aspects of the Structural Health Monitoring process that should be standardized in order to provide the stakeholders with consensual procedures for their implementation and use on the lifecycle, thereby improving the diffusion of such systems at a large scale on structures and infrastructures
Vibration-based structural health monitoring: Challenges and opportunities
Full text linkIn the last twenty years vibration-based methods for Structural Health Monitoring (SHM) have received increasing attention by both academics and operators, due to undoubtable advantages they provide for damage identification purposes. These are mainly related to the capability of providing continuous information about the global state of the structure without a prior knowledge about the location of possible damages and without the need to access the damaged portion of the structure. These methods rely on the fact that a damage inducing a loss of stiffness results in a change of the dynamic behavior therefore, structural responses to forced or ambient vibrations can be used to retrieve information about these changes. Despite the large amount of literature published on these methods, their experimental validation is often limited to highly controlled laboratory conditions or numerical simulations. The validation of the algorithms on real damaged structures is often hampered by the unavailability of data and this constitutes indeed a challenge for the implementation of these techniques at the operational level. In the first part of this paper the possible drawbacks related to the effect of uncertainties related to the effect of environmental sources, noise in hardware systems for the acquisition and transmission of structural responses and approximations in the adopted models. Another aspect that has slow down the practical diffusion of these methods, and generally of SHM techniques, is the difficulty to quantify their benefits prior to their implementation. This has sometime restraint the operators from investing on them, despite the several advantages these systems offer in terms of maintenance optimization and emergency management. In the paper some recent research efforts on several aspects related to the development and implementation of these methods are illustrated
Experimental verification of the interpolation method on a real damaged bridge
Full text linkThe identification of damage in a bridge from changes in its vibrational behavior is an
inverse problem of important practical value. Significant advances have been obtained on this
topic in the last two-three decades, both from the theoretical and applied point of view. One of
the main problems when dealing with the assessment of vibration based damage identification
methods is the lack of experimental data recorded on real damaged structures. Due to this, a large
number of damage identification algorithms are tested using data simulated by numerical
models. The availability of data recorded on a damaged bridge before its demolition gave the
authors the uncommon chance to verify the sensitivity and reliability of the IDDM basing on
data recorded on a real structure. Specifically data recorded on a reinforced concrete single-span
supported bridge in the Municipality of Dogna (Friuli, Italy) were used to apply the damage
localization algorithm. Harmonically forced tests were conducted after imposing artificial,
increasing levels of localized damage. In this paper the sensitivity of the method is discussed
with respect to the number of instrumented locations and to the severity of the damage scenarios
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Value of vibration-based structural monitoring for bridge emergency management
No full textContinuous monitoring of the structural response to vibrations enables to acquire real-time information that can support asset management decisions. Despite the several advantages provided by the availability of continuously updated information, the adoption of vibration-based monitoring systems still encounters difficulties to be implemented at large scale due to their perceived high cost and the difficulty to estimate the return on investment before their implementation. The Value of Information (VoI) analysis from Bayesian decision theory can be used to quantify the benefits associated with vibration-based monitoring information in supporting the selection of optimal asset management actions. In this paper, a framework to quantify the VoI from vibration-based monitoring is outlined, the principal ‘ingredients’ needed for its implementation are described, and examples of its application for emergency managements are used to illustrate the general framework
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