2022
Journal article
Open Access
Tracking the variation of complex mode shapes for damage quantification and localization in structural systems
Masciotta Mg, Pellegrini D
Real structures mode shapes estimated by modal analysis techniques have a common feature: in most cases they are complex, and their level of complexity can be soundly influenced by the presence and extent of physical damage, which also affects the distribution of energy dissipation mechanisms within... the structures. Starting from the contributions available in the literature, the present paper investigates, from a numerical and experimental point of view, the correlation existing between localized damage and variation of global modal complexity indices conventionally employed to quantify the nonproportionality of damping in structural systems. Finally, driven by the inferences made through numerical and experimental test cases by tracking the variation of complex modes over multiple and progressive damage scenarios, a new index for damage localization and quantification is formulated and validated against real data. [show more]Source: MECHANICAL SYSTEMS AND SIGNAL PROCESSING, vol. 169
DOI: 10.1016/j.ymssp.2021.108731
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Masciotta Mg, Pellegrini D
Real structures mode shapes estimated by modal analysis techniques have a common feature: in most cases they are complex, and their level of complexity can be soundly influenced by the presence and extent of physical damage, which also affects the distribution of energy dissipation mechanisms within... the structures. Starting from the contributions available in the literature, the present paper investigates, from a numerical and experimental point of view, the correlation existing between localized damage and variation of global modal complexity indices conventionally employed to quantify the nonproportionality of damping in structural systems. Finally, driven by the inferences made through numerical and experimental test cases by tracking the variation of complex modes over multiple and progressive damage scenarios, a new index for damage localization and quantification is formulated and validated against real data. [show more]Source: MECHANICAL SYSTEMS AND SIGNAL PROCESSING, vol. 169
DOI: 10.1016/j.ymssp.2021.108731
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2024
Conference article
Open Access
Investigating the relation between complex mode shapes and local damage for structural assessment
Masciotta M. G., Pellegrini D.
Modal parameters define the inherent characteristics of real-world structures, being therefore employed as reference information for various purposes, including the assessment of structural damage, the evaluation of operational and environmental effects, and the calibration of realistic numerical mo... dels. Among frequencies, damping ratios and mode shapes, the latter have been proved far more effective in localizing structural damage given their spatial dependency on the nodal coordinates of vibrating systems. Most of modal analysis applications resort to the real part of these quantities for vibration-based damage identification of structural systems, assuming them as classically damped. However, the classical viscous damping assumption is often idealistic for real-world structures as the damping matrix cannot be considered as proportional to mass and stiffness matrices. It follows that the mode shapes of real systems are complex in nature, and their complexity level can vary with damage. Based on the above considerations, this work intends to shed light on the relationship between structural damage and modal complexity. Numerical investigations are carried out to track the variation of complex mode shapes in a multi-span bridge subjected to progressive damage scenarios and to infer about the generalization of a new index that relies on the variation of the imaginary content of complex eigenmodes to detect, locate and assess the structural damage. [show more]Source: JOURNAL OF PHYSICS. CONFERENCE SERIES, vol. 2647 (issue 19). Delft, The Netherlands, 02-05 July 2023
DOI: 10.1088/1742-6596/2647/19/192024
Metrics:
Masciotta M. G., Pellegrini D.
Modal parameters define the inherent characteristics of real-world structures, being therefore employed as reference information for various purposes, including the assessment of structural damage, the evaluation of operational and environmental effects, and the calibration of realistic numerical mo... dels. Among frequencies, damping ratios and mode shapes, the latter have been proved far more effective in localizing structural damage given their spatial dependency on the nodal coordinates of vibrating systems. Most of modal analysis applications resort to the real part of these quantities for vibration-based damage identification of structural systems, assuming them as classically damped. However, the classical viscous damping assumption is often idealistic for real-world structures as the damping matrix cannot be considered as proportional to mass and stiffness matrices. It follows that the mode shapes of real systems are complex in nature, and their complexity level can vary with damage. Based on the above considerations, this work intends to shed light on the relationship between structural damage and modal complexity. Numerical investigations are carried out to track the variation of complex mode shapes in a multi-span bridge subjected to progressive damage scenarios and to infer about the generalization of a new index that relies on the variation of the imaginary content of complex eigenmodes to detect, locate and assess the structural damage. [show more]Source: JOURNAL OF PHYSICS. CONFERENCE SERIES, vol. 2647 (issue 19). Delft, The Netherlands, 02-05 July 2023
DOI: 10.1088/1742-6596/2647/19/192024
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Journal of Physics : Conference Series | IRIS Cnr | IRIS Cnr | ARUdA | ARUdA | CNR IRIS
2024
Conference article
Open Access
Optimal sensor placement for bridge structural health monitoring: integration of physics-based models with data-driven approaches
Masciotta M. G., Barontini A., Pellegrini D., Brando G., Lourenço P. B.
Optimization of sensor configurations for cost-efficient structural health monitoring (SHM) plays a pivotal role in ensuring the safety and longevity of critical infrastructures such as bridges while minimizing maintenance expenses. Infrastructure systems may evolve over time, and their monitoring n... eeds may change. Hence, the best sensor configuration must be designed to be scalable and adaptable to future requirements without major overhauls. The present work explores this optimization problem as an essential step of the development and implementation of a robust digital twinning strategy, by combining the strengths of physics-based models with data-driven insights. Conventional methods for sensor placement typically rely on expert knowledge, oftentimes resulting in suboptimal configurations and excessive installation costs. Conversely, physics-based models provide a rigorous comprehension of the structural behavior and can inform sensor placement procedures by assessing the impact of sensor locations on the monitoring accuracy. However, these models have limitations, such as simplifying assumptions, uncertainties, and computational complexities. To overcome these issues and upgrade the sensor placement process, data-driven approaches can be integrated to extract patterns, correlations, and unforeseen anomalies. To demonstrate the effectiveness and benefits of this hybrid framework, a case study of an existing bridge instrumented with sensors is presented. First, a simplified physics-based model is developed and calibrated through real-world data obtained from an extensive dynamic identification campaign comprising 108 instrumented degrees of freedom. Then, a reduced number of sensors are selected through a data-driven optimization strategy as best candidates for the deployment of a long-term monitoring system. Finally, the virtual model is employed to simulate varying damage scenarios and validate whether the sensor location experimentally identified as optimal would remain the best even when structural conditions change. The ultimate goal is to foster proactive maintenance strategies by striking a balance between data quality, sensor coverage, and SHM cost. [show more]Source: PROCEDIA STRUCTURAL INTEGRITY, vol. 62, pp. 932-939
DOI: 10.1016/j.prostr.2024.09.125
Metrics:
Masciotta M. G., Barontini A., Pellegrini D., Brando G., Lourenço P. B.
Optimization of sensor configurations for cost-efficient structural health monitoring (SHM) plays a pivotal role in ensuring the safety and longevity of critical infrastructures such as bridges while minimizing maintenance expenses. Infrastructure systems may evolve over time, and their monitoring n... eeds may change. Hence, the best sensor configuration must be designed to be scalable and adaptable to future requirements without major overhauls. The present work explores this optimization problem as an essential step of the development and implementation of a robust digital twinning strategy, by combining the strengths of physics-based models with data-driven insights. Conventional methods for sensor placement typically rely on expert knowledge, oftentimes resulting in suboptimal configurations and excessive installation costs. Conversely, physics-based models provide a rigorous comprehension of the structural behavior and can inform sensor placement procedures by assessing the impact of sensor locations on the monitoring accuracy. However, these models have limitations, such as simplifying assumptions, uncertainties, and computational complexities. To overcome these issues and upgrade the sensor placement process, data-driven approaches can be integrated to extract patterns, correlations, and unforeseen anomalies. To demonstrate the effectiveness and benefits of this hybrid framework, a case study of an existing bridge instrumented with sensors is presented. First, a simplified physics-based model is developed and calibrated through real-world data obtained from an extensive dynamic identification campaign comprising 108 instrumented degrees of freedom. Then, a reduced number of sensors are selected through a data-driven optimization strategy as best candidates for the deployment of a long-term monitoring system. Finally, the virtual model is employed to simulate varying damage scenarios and validate whether the sensor location experimentally identified as optimal would remain the best even when structural conditions change. The ultimate goal is to foster proactive maintenance strategies by striking a balance between data quality, sensor coverage, and SHM cost. [show more]Source: PROCEDIA STRUCTURAL INTEGRITY, vol. 62, pp. 932-939
DOI: 10.1016/j.prostr.2024.09.125
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Procedia Structural Integrity | IRIS Cnr | IRIS Cnr | CNR IRIS
2020
Journal article
Open Access
Dynamic characterization of progressively damaged segmental masonry arches with one settled support: experimental and numerical analyses
Masciotta M. G., Pellegrini D., Girardi M., Padovani C., Barontini A., Lourenço P. B., Brigante D., Fabbrocino G.
This paper aims to explore the dynamic behavior of a segmental masonry arch subjected to increasing horizontal displacements of one support. To this end, output-only dynamic identification techniques are first used to track the evolution of the dynamic features of the system under progressive damage... scenarios and evaluate their sensitivity to settlement-induced cracks. Considerations on the structural response of the segmental arch up to failure are also included. Then, a numerical procedure coupling linear perturbation and modal analysis is applied to simulate the dynamic behavior of the arch over consecutive scenarios, taking into account the influence of the damage on the structure's dynamic properties in an automatic way. The combination of experimental and numerical analyses allows to fully investigate the dynamics of the cracked masonry arch and to shed light on relevant aspects about the effects of settlement-induced cracks on the modal blueprints of masonry arches. [show more]Source: FRATTURA E INTEGRITÀ STRUTTURALE
DOI: 10.3221/igf-esis.51.31
Metrics:
Masciotta M. G., Pellegrini D., Girardi M., Padovani C., Barontini A., Lourenço P. B., Brigante D., Fabbrocino G.
This paper aims to explore the dynamic behavior of a segmental masonry arch subjected to increasing horizontal displacements of one support. To this end, output-only dynamic identification techniques are first used to track the evolution of the dynamic features of the system under progressive damage... scenarios and evaluate their sensitivity to settlement-induced cracks. Considerations on the structural response of the segmental arch up to failure are also included. Then, a numerical procedure coupling linear perturbation and modal analysis is applied to simulate the dynamic behavior of the arch over consecutive scenarios, taking into account the influence of the damage on the structure's dynamic properties in an automatic way. The combination of experimental and numerical analyses allows to fully investigate the dynamics of the cracked masonry arch and to shed light on relevant aspects about the effects of settlement-induced cracks on the modal blueprints of masonry arches. [show more]Source: FRATTURA E INTEGRITÀ STRUTTURALE
DOI: 10.3221/igf-esis.51.31
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Frattura ed Integrità Strutturale | Universidade do Minho: RepositoriUM | CNR IRIS | ISTI Repository | Frattura ed Integrità Strutturale | Fracture and Structural Integrity | CNR IRIS
2020
Conference article
Open Access
A multidisciplinary approach integrating geomatics, dynamic field testing and finite element modelling to evaluate the conservation state of the guimaraes castle's tower keep
Sánchezaparicio Lj, Masciotta Mg, Pellegrini D, Conde B, Girardi M, Padovani C, Ramos Lf, Riveiro B
The development of realistic numerical models able to replicate as closely as possible the actual structural behaviour of heritage buildings is crucial for a thorough assessment of their structur-al performance against exceptional scenarios. In this regard, higher accuracy can be achieved by leverag... ing a multidisciplinary approach that integrates multiple contributions from different fields, such as geomatics, dynamics and computational modelling.In the present paper, this strategy is applied to the tower keep of the Guimarães castle, in Por-tugal, a masonry fortified structure dating back to the X century. Starting from an accurate la-ser scanner survey, a detailed numerical model has been created resorting to efficient algo-rithms able to represent complex situations. Furthermore, by exploiting the dynamic properties extracted from the processing of vibration data collected during field dynamic testing, the me-chanical characteristics of the constituent materials of the tower have been estimated by means of a model updating technique embedded in a trust-region scheme implemented in the NOSA-ITACA code. The results obtained so far allowed to establish valuable baseline information that will be of pivotal importance to catch possible changes in the tower's response and to perform more in-depth structural analyses. [show more]
Sánchezaparicio Lj, Masciotta Mg, Pellegrini D, Conde B, Girardi M, Padovani C, Ramos Lf, Riveiro B
The development of realistic numerical models able to replicate as closely as possible the actual structural behaviour of heritage buildings is crucial for a thorough assessment of their structur-al performance against exceptional scenarios. In this regard, higher accuracy can be achieved by leverag... ing a multidisciplinary approach that integrates multiple contributions from different fields, such as geomatics, dynamics and computational modelling.In the present paper, this strategy is applied to the tower keep of the Guimarães castle, in Por-tugal, a masonry fortified structure dating back to the X century. Starting from an accurate la-ser scanner survey, a detailed numerical model has been created resorting to efficient algo-rithms able to represent complex situations. Furthermore, by exploiting the dynamic properties extracted from the processing of vibration data collected during field dynamic testing, the me-chanical characteristics of the constituent materials of the tower have been estimated by means of a model updating technique embedded in a trust-region scheme implemented in the NOSA-ITACA code. The results obtained so far allowed to establish valuable baseline information that will be of pivotal importance to catch possible changes in the tower's response and to perform more in-depth structural analyses. [show more]
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eurodyn2020.org | CNR IRIS | ISTI Repository | CNR IRIS
2024
Conference article
Open Access
Leveraging advanced numerical calibration to filter out temperature effects on vibration-based monitoring data: application to the Mogadouro clock tower
Barontini A., Pellegrini D., Testa F., Girardi M., Masciotta M., Mendes N., Padovani C.
This study investigates the advantages of integrating physics knowledge to enhance traditional data-driven methods for damage detection and early warning in a monitored structure. The implemented method combines the ability to predict variations in modal properties (such as natural frequencies) unde... r changing temperatures, using a highly reliable Finite Element (FE) model calibrated to the experimental response of the structure, with a robust anomaly detection strategy to process new monitoring data and classify it as damaged or undamaged. The relationship between temperature and modal properties, as evaluated through the FE model, is used to normalise the monitoring data. This process filters out the effects of the environmental variation, potentially magnifying the effects of damage, which are then investigated through machine learning algorithms for classification purpose. The procedure is validated by analysing a real case study, the Mogadouro clock tower in Portugal. Several scenarios of available knowledge during the training of the damage detection strategy are simulated, discussing advantages and identifying areas for future improvement. [show more]DOI: 10.23967/eccomas.2024.247
Metrics:
Barontini A., Pellegrini D., Testa F., Girardi M., Masciotta M., Mendes N., Padovani C.
This study investigates the advantages of integrating physics knowledge to enhance traditional data-driven methods for damage detection and early warning in a monitored structure. The implemented method combines the ability to predict variations in modal properties (such as natural frequencies) unde... r changing temperatures, using a highly reliable Finite Element (FE) model calibrated to the experimental response of the structure, with a robust anomaly detection strategy to process new monitoring data and classify it as damaged or undamaged. The relationship between temperature and modal properties, as evaluated through the FE model, is used to normalise the monitoring data. This process filters out the effects of the environmental variation, potentially magnifying the effects of damage, which are then investigated through machine learning algorithms for classification purpose. The procedure is validated by analysing a real case study, the Mogadouro clock tower in Portugal. Several scenarios of available knowledge during the training of the damage detection strategy are simulated, discussing advantages and identifying areas for future improvement. [show more]DOI: 10.23967/eccomas.2024.247
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CNR IRIS | www.scipedia.com | CNR IRIS